Update contrib/restricted/abseil-cpp-tstring to 20240722.0

83a5727000e16bc5a94523a0cf1cce75fa86a191

129 files changed, 7566 insertions, 2499 deletions

diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/container.h b/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/container.h
index 09864bb868..cf52565726 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/container.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/container.h
@@ -44,6 +44,7 @@
 #include <cassert>
 #include <iterator>
 #include <numeric>
+#include <random>
 #include <type_traits>
 #include <unordered_map>
 #include <unordered_set>
@@ -51,6 +52,7 @@
 #include <vector>
 
 #include "y_absl/algorithm/algorithm.h"
+#include "y_absl/base/config.h"
 #include "y_absl/base/macros.h"
 #include "y_absl/base/nullability.h"
 #include "y_absl/meta/type_traits.h"
@@ -92,17 +94,17 @@ using ContainerPointerType =
 //   using std::end;
 //   std::foo(begin(c), end(c));
 // becomes
-//   std::foo(container_algorithm_internal::begin(c),
-//            container_algorithm_internal::end(c));
+//   std::foo(container_algorithm_internal::c_begin(c),
+//            container_algorithm_internal::c_end(c));
 // These are meant for internal use only.
 
 template <typename C>
-ContainerIter<C> c_begin(C& c) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17 ContainerIter<C> c_begin(C& c) {
   return begin(c);
 }
 
 template <typename C>
-ContainerIter<C> c_end(C& c) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17 ContainerIter<C> c_end(C& c) {
   return end(c);
 }
 
@@ -145,8 +147,9 @@ bool c_linear_search(const C& c, EqualityComparable&& value) {
 // Container-based version of the <iterator> `std::distance()` function to
 // return the number of elements within a container.
 template <typename C>
-container_algorithm_internal::ContainerDifferenceType<const C> c_distance(
-    const C& c) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerDifferenceType<const C>
+    c_distance(const C& c) {
   return std::distance(container_algorithm_internal::c_begin(c),
                        container_algorithm_internal::c_end(c));
 }
@@ -210,6 +213,16 @@ container_algorithm_internal::ContainerIter<C> c_find(C& c, T&& value) {
                    std::forward<T>(value));
 }
 
+// c_contains()
+//
+// Container-based version of the <algorithm> `std::ranges::contains()` C++23
+// function to search a container for a value.
+template <typename Sequence, typename T>
+bool c_contains(const Sequence& sequence, T&& value) {
+  return y_absl::c_find(sequence, std::forward<T>(value)) !=
+         container_algorithm_internal::c_end(sequence);
+}
+
 // c_find_if()
 //
 // Container-based version of the <algorithm> `std::find_if()` function to find
@@ -426,6 +439,26 @@ container_algorithm_internal::ContainerIter<Sequence1> c_search(
                      std::forward<BinaryPredicate>(pred));
 }
 
+// c_contains_subrange()
+//
+// Container-based version of the <algorithm> `std::ranges::contains_subrange()`
+// C++23 function to search a container for a subsequence.
+template <typename Sequence1, typename Sequence2>
+bool c_contains_subrange(Sequence1& sequence, Sequence2& subsequence) {
+  return y_absl::c_search(sequence, subsequence) !=
+         container_algorithm_internal::c_end(sequence);
+}
+
+// Overload of c_contains_subrange() for using a predicate evaluation other than
+// `==` as the function's test condition.
+template <typename Sequence1, typename Sequence2, typename BinaryPredicate>
+bool c_contains_subrange(Sequence1& sequence, Sequence2& subsequence,
+                         BinaryPredicate&& pred) {
+  return y_absl::c_search(sequence, subsequence,
+                        std::forward<BinaryPredicate>(pred)) !=
+         container_algorithm_internal::c_end(sequence);
+}
+
 // c_search_n()
 //
 // Container-based version of the <algorithm> `std::search_n()` function to
@@ -1500,8 +1533,9 @@ c_is_heap_until(RandomAccessContainer& sequence, LessThan&& comp) {
 // to return an iterator pointing to the element with the smallest value, using
 // `operator<` to make the comparisons.
 template <typename Sequence>
-container_algorithm_internal::ContainerIter<Sequence> c_min_element(
-    Sequence& sequence) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerIter<Sequence>
+    c_min_element(Sequence& sequence) {
   return std::min_element(container_algorithm_internal::c_begin(sequence),
                           container_algorithm_internal::c_end(sequence));
 }
@@ -1509,8 +1543,9 @@ container_algorithm_internal::ContainerIter<Sequence> c_min_element(
 // Overload of c_min_element() for performing a `comp` comparison other than
 // `operator<`.
 template <typename Sequence, typename LessThan>
-container_algorithm_internal::ContainerIter<Sequence> c_min_element(
-    Sequence& sequence, LessThan&& comp) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerIter<Sequence>
+    c_min_element(Sequence& sequence, LessThan&& comp) {
   return std::min_element(container_algorithm_internal::c_begin(sequence),
                           container_algorithm_internal::c_end(sequence),
                           std::forward<LessThan>(comp));
@@ -1522,8 +1557,9 @@ container_algorithm_internal::ContainerIter<Sequence> c_min_element(
 // to return an iterator pointing to the element with the largest value, using
 // `operator<` to make the comparisons.
 template <typename Sequence>
-container_algorithm_internal::ContainerIter<Sequence> c_max_element(
-    Sequence& sequence) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerIter<Sequence>
+    c_max_element(Sequence& sequence) {
   return std::max_element(container_algorithm_internal::c_begin(sequence),
                           container_algorithm_internal::c_end(sequence));
 }
@@ -1531,8 +1567,9 @@ container_algorithm_internal::ContainerIter<Sequence> c_max_element(
 // Overload of c_max_element() for performing a `comp` comparison other than
 // `operator<`.
 template <typename Sequence, typename LessThan>
-container_algorithm_internal::ContainerIter<Sequence> c_max_element(
-    Sequence& sequence, LessThan&& comp) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerIter<Sequence>
+    c_max_element(Sequence& sequence, LessThan&& comp) {
   return std::max_element(container_algorithm_internal::c_begin(sequence),
                           container_algorithm_internal::c_end(sequence),
                           std::forward<LessThan>(comp));
@@ -1545,8 +1582,9 @@ container_algorithm_internal::ContainerIter<Sequence> c_max_element(
 // smallest and largest values, respectively, using `operator<` to make the
 // comparisons.
 template <typename C>
-container_algorithm_internal::ContainerIterPairType<C, C> c_minmax_element(
-    C& c) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerIterPairType<C, C>
+    c_minmax_element(C& c) {
   return std::minmax_element(container_algorithm_internal::c_begin(c),
                              container_algorithm_internal::c_end(c));
 }
@@ -1554,8 +1592,9 @@ container_algorithm_internal::ContainerIterPairType<C, C> c_minmax_element(
 // Overload of c_minmax_element() for performing `comp` comparisons other than
 // `operator<`.
 template <typename C, typename LessThan>
-container_algorithm_internal::ContainerIterPairType<C, C> c_minmax_element(
-    C& c, LessThan&& comp) {
+Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+    container_algorithm_internal::ContainerIterPairType<C, C>
+    c_minmax_element(C& c, LessThan&& comp) {
   return std::minmax_element(container_algorithm_internal::c_begin(c),
                              container_algorithm_internal::c_end(c),
                              std::forward<LessThan>(comp));
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/ya.make
index ac5695f072..467248d279 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/algorithm/ya.make
@@ -6,9 +6,9 @@ LICENSE(Apache-2.0)
 
 LICENSE_TEXTS(.yandex_meta/licenses.list.txt)
 
-VERSION(20240116.2)
+VERSION(20240722.0)
 
-ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240116.2.tar.gz)
+ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz)
 
 NO_RUNTIME()
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/attributes.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/attributes.h
index 8865a7a294..5818c13615 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/attributes.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/attributes.h
@@ -195,6 +195,9 @@
 // Y_ABSL_ATTRIBUTE_NORETURN
 //
 // Tells the compiler that a given function never returns.
+//
+// Deprecated: Prefer the `[[noreturn]]` attribute standardized by C++11 over
+// this macro.
 #if Y_ABSL_HAVE_ATTRIBUTE(noreturn) || (defined(__GNUC__) && !defined(__clang__))
 #define Y_ABSL_ATTRIBUTE_NORETURN __attribute__((noreturn))
 #elif defined(_MSC_VER)
@@ -702,6 +705,11 @@
   _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
 #define Y_ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING \
   _Pragma("GCC diagnostic pop")
+#elif defined(_MSC_VER)
+#define Y_ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING \
+  _Pragma("warning(push)") _Pragma("warning(disable: 4996)")
+#define Y_ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING \
+  _Pragma("warning(pop)")
 #else
 #define Y_ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
 #define Y_ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
@@ -808,14 +816,43 @@
 //
 // See also the upstream documentation:
 // https://clang.llvm.org/docs/AttributeReference.html#lifetimebound
+// https://learn.microsoft.com/en-us/cpp/code-quality/c26816?view=msvc-170
 #if Y_ABSL_HAVE_CPP_ATTRIBUTE(clang::lifetimebound)
 #define Y_ABSL_ATTRIBUTE_LIFETIME_BOUND [[clang::lifetimebound]]
+#elif Y_ABSL_HAVE_CPP_ATTRIBUTE(msvc::lifetimebound)
+#define Y_ABSL_ATTRIBUTE_LIFETIME_BOUND [[msvc::lifetimebound]]
 #elif Y_ABSL_HAVE_ATTRIBUTE(lifetimebound)
 #define Y_ABSL_ATTRIBUTE_LIFETIME_BOUND __attribute__((lifetimebound))
 #else
 #define Y_ABSL_ATTRIBUTE_LIFETIME_BOUND
 #endif
 
+// Y_ABSL_INTERNAL_ATTRIBUTE_VIEW indicates that a type acts like a view i.e. a
+// raw (non-owning) pointer. This enables diagnoses similar to those enabled by
+// Y_ABSL_ATTRIBUTE_LIFETIME_BOUND.
+//
+// See the following links for details:
+// https://reviews.llvm.org/D64448
+// https://lists.llvm.org/pipermail/cfe-dev/2018-November/060355.html
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(gsl::Pointer)
+#define Y_ABSL_INTERNAL_ATTRIBUTE_VIEW [[gsl::Pointer]]
+#else
+#define Y_ABSL_INTERNAL_ATTRIBUTE_VIEW
+#endif
+
+// Y_ABSL_INTERNAL_ATTRIBUTE_OWNER indicates that a type acts like a smart
+// (owning) pointer. This enables diagnoses similar to those enabled by
+// Y_ABSL_ATTRIBUTE_LIFETIME_BOUND.
+//
+// See the following links for details:
+// https://reviews.llvm.org/D64448
+// https://lists.llvm.org/pipermail/cfe-dev/2018-November/060355.html
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(gsl::Owner)
+#define Y_ABSL_INTERNAL_ATTRIBUTE_OWNER [[gsl::Owner]]
+#else
+#define Y_ABSL_INTERNAL_ATTRIBUTE_OWNER
+#endif
+
 // Y_ABSL_ATTRIBUTE_TRIVIAL_ABI
 // Indicates that a type is "trivially relocatable" -- meaning it can be
 // relocated without invoking the constructor/destructor, using a form of move
@@ -871,4 +908,51 @@
 #define Y_ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS
 #endif
 
+// Y_ABSL_ATTRIBUTE_UNINITIALIZED
+//
+// GCC and Clang support a flag `-ftrivial-auto-var-init=<option>` (<option>
+// can be "zero" or "pattern") that can be used to initialize automatic stack
+// variables. Variables with this attribute will be left uninitialized,
+// overriding the compiler flag.
+//
+// See https://clang.llvm.org/docs/AttributeReference.html#uninitialized
+// and https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-uninitialized-variable-attribute
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(clang::uninitialized)
+#define Y_ABSL_ATTRIBUTE_UNINITIALIZED [[clang::uninitialized]]
+#elif Y_ABSL_HAVE_CPP_ATTRIBUTE(gnu::uninitialized)
+#define Y_ABSL_ATTRIBUTE_UNINITIALIZED [[gnu::uninitialized]]
+#elif Y_ABSL_HAVE_ATTRIBUTE(uninitialized)
+#define Y_ABSL_ATTRIBUTE_UNINITIALIZED __attribute__((uninitialized))
+#else
+#define Y_ABSL_ATTRIBUTE_UNINITIALIZED
+#endif
+
+// Y_ABSL_ATTRIBUTE_WARN_UNUSED
+//
+// Compilers routinely warn about trivial variables that are unused.  For
+// non-trivial types, this warning is suppressed since the
+// constructor/destructor may be intentional and load-bearing, for example, with
+// a RAII scoped lock.
+//
+// For example:
+//
+// class Y_ABSL_ATTRIBUTE_WARN_UNUSED MyType {
+//  public:
+//   MyType();
+//   ~MyType();
+// };
+//
+// void foo() {
+//   // Warns with Y_ABSL_ATTRIBUTE_WARN_UNUSED attribute present.
+//   MyType unused;
+// }
+//
+// See https://clang.llvm.org/docs/AttributeReference.html#warn-unused and
+// https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Attributes.html#index-warn_005funused-type-attribute
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(gnu::warn_unused)
+#define Y_ABSL_ATTRIBUTE_WARN_UNUSED [[gnu::warn_unused]]
+#else
+#define Y_ABSL_ATTRIBUTE_WARN_UNUSED
+#endif
+
 #endif  // Y_ABSL_BASE_ATTRIBUTES_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/config.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/config.h
index 22bbf3c0b5..58bafcd829 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/config.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/config.h
@@ -117,8 +117,8 @@
 //
 // LTS releases can be obtained from
 // https://github.com/abseil/abseil-cpp/releases.
-#define Y_ABSL_LTS_RELEASE_VERSION 20240116
-#define Y_ABSL_LTS_RELEASE_PATCH_LEVEL 2
+#define Y_ABSL_LTS_RELEASE_VERSION 20240722
+#define Y_ABSL_LTS_RELEASE_PATCH_LEVEL 0
 
 // Helper macro to convert a CPP variable to a string literal.
 #define Y_ABSL_INTERNAL_DO_TOKEN_STR(x) #x
@@ -231,12 +231,11 @@ static_assert(Y_ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #endif
 
 // Y_ABSL_HAVE_TLS is defined to 1 when __thread should be supported.
-// We assume __thread is supported on Linux or Asylo when compiled with Clang or
+// We assume __thread is supported on Linux when compiled with Clang or
 // compiled against libstdc++ with _GLIBCXX_HAVE_TLS defined.
 #ifdef Y_ABSL_HAVE_TLS
 #error Y_ABSL_HAVE_TLS cannot be directly set
-#elif (defined(__linux__) || defined(__ASYLO__)) && \
-    (defined(__clang__) || defined(_GLIBCXX_HAVE_TLS))
+#elif (defined(__linux__)) && (defined(__clang__) || defined(_GLIBCXX_HAVE_TLS))
 #define Y_ABSL_HAVE_TLS 1
 #endif
 
@@ -275,53 +274,18 @@ static_assert(Y_ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #define Y_ABSL_HAVE_STD_IS_TRIVIALLY_COPYABLE 1
 #endif
 
+
 // Y_ABSL_HAVE_THREAD_LOCAL
 //
+// DEPRECATED - `thread_local` is available on all supported platforms.
 // Checks whether C++11's `thread_local` storage duration specifier is
 // supported.
 #ifdef Y_ABSL_HAVE_THREAD_LOCAL
 #error Y_ABSL_HAVE_THREAD_LOCAL cannot be directly set
-#elif defined(__APPLE__)
-// Notes:
-// * Xcode's clang did not support `thread_local` until version 8, and
-//   even then not for all iOS < 9.0.
-// * Xcode 9.3 started disallowing `thread_local` for 32-bit iOS simulator
-//   targeting iOS 9.x.
-// * Xcode 10 moves the deployment target check for iOS < 9.0 to link time
-//   making Y_ABSL_HAVE_FEATURE unreliable there.
-//
-#if Y_ABSL_HAVE_FEATURE(cxx_thread_local) && \
-    !(TARGET_OS_IPHONE && __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_9_0)
-#define Y_ABSL_HAVE_THREAD_LOCAL 1
-#endif
-#else  // !defined(__APPLE__)
+#else
 #define Y_ABSL_HAVE_THREAD_LOCAL 1
 #endif
 
-// There are platforms for which TLS should not be used even though the compiler
-// makes it seem like it's supported (Android NDK < r12b for example).
-// This is primarily because of linker problems and toolchain misconfiguration:
-// Abseil does not intend to support this indefinitely. Currently, the newest
-// toolchain that we intend to support that requires this behavior is the
-// r11 NDK - allowing for a 5 year support window on that means this option
-// is likely to be removed around June of 2021.
-// TLS isn't supported until NDK r12b per
-// https://developer.android.com/ndk/downloads/revision_history.html
-// Since NDK r16, `__NDK_MAJOR__` and `__NDK_MINOR__` are defined in
-// <android/ndk-version.h>. For NDK < r16, users should define these macros,
-// e.g. `-D__NDK_MAJOR__=11 -D__NKD_MINOR__=0` for NDK r11.
-#if defined(__ANDROID__) && defined(__clang__)
-#if __has_include(<android/ndk-version.h>)
-#include <android/ndk-version.h>
-#endif  // __has_include(<android/ndk-version.h>)
-#if defined(__ANDROID__) && defined(__clang__) && defined(__NDK_MAJOR__) && \
-    defined(__NDK_MINOR__) &&                                               \
-    ((__NDK_MAJOR__ < 12) || ((__NDK_MAJOR__ == 12) && (__NDK_MINOR__ < 1)))
-#undef Y_ABSL_HAVE_TLS
-#undef Y_ABSL_HAVE_THREAD_LOCAL
-#endif
-#endif  // defined(__ANDROID__) && defined(__clang__)
-
 // Y_ABSL_HAVE_INTRINSIC_INT128
 //
 // Checks whether the __int128 compiler extension for a 128-bit integral type is
@@ -379,9 +343,7 @@ static_assert(Y_ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #define Y_ABSL_HAVE_EXCEPTIONS 1
 #endif  // defined(__EXCEPTIONS) && Y_ABSL_HAVE_FEATURE(cxx_exceptions)
 // Handle remaining special cases and default to exceptions being supported.
-#elif !(defined(__GNUC__) && (__GNUC__ < 5) && !defined(__EXCEPTIONS)) && \
-    !(Y_ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(5, 0) &&                        \
-      !defined(__cpp_exceptions)) &&                                      \
+#elif !(defined(__GNUC__) && !defined(__cpp_exceptions)) && \
     !(defined(_MSC_VER) && !defined(_CPPUNWIND))
 #define Y_ABSL_HAVE_EXCEPTIONS 1
 #endif
@@ -416,9 +378,9 @@ static_assert(Y_ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) ||    \
     defined(_AIX) || defined(__ros__) || defined(__native_client__) ||       \
     defined(__asmjs__) || defined(__EMSCRIPTEN__) || defined(__Fuchsia__) || \
-    defined(__sun) || defined(__ASYLO__) || defined(__myriad2__) ||          \
-    defined(__HAIKU__) || defined(__OpenBSD__) || defined(__NetBSD__) ||     \
-    defined(__QNX__) || defined(__VXWORKS__) || defined(__hexagon__)
+    defined(__sun) || defined(__myriad2__) || defined(__HAIKU__) ||          \
+    defined(__OpenBSD__) || defined(__NetBSD__) || defined(__QNX__) ||       \
+    defined(__VXWORKS__) || defined(__hexagon__)
 #define Y_ABSL_HAVE_MMAP 1
 #endif
 
@@ -902,9 +864,7 @@ static_assert(Y_ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #error Y_ABSL_INTERNAL_HAS_CXA_DEMANGLE cannot be directly set
 #elif defined(OS_ANDROID) && (defined(__i386__) || defined(__x86_64__))
 #define Y_ABSL_INTERNAL_HAS_CXA_DEMANGLE 0
-#elif defined(__GNUC__) && defined(__GNUC_MINOR__) &&            \
-    (__GNUC__ >= 4 || (__GNUC__ >= 3 && __GNUC_MINOR__ >= 4)) && \
-    !defined(__mips__)
+#elif defined(__GNUC__)
 #define Y_ABSL_INTERNAL_HAS_CXA_DEMANGLE 1
 #elif defined(__clang__) && !defined(_MSC_VER)
 #define Y_ABSL_INTERNAL_HAS_CXA_DEMANGLE 1
@@ -981,6 +941,27 @@ static_assert(Y_ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #define Y_ABSL_HAVE_CONSTANT_EVALUATED 1
 #endif
 
+// Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXXYY is used to conditionally define constexpr
+// for different C++ versions.
+//
+// These macros are an implementation detail and will be unconditionally removed
+// once the minimum supported C++ version catches up to a given version.
+//
+// For this reason, this symbol is considered INTERNAL and code outside of
+// Abseil must not use it.
+#if defined(Y_ABSL_INTERNAL_CPLUSPLUS_LANG) && \
+    Y_ABSL_INTERNAL_CPLUSPLUS_LANG >= 201703L
+#define Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17 constexpr
+#else
+#define Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX17
+#endif
+#if defined(Y_ABSL_INTERNAL_CPLUSPLUS_LANG) && \
+    Y_ABSL_INTERNAL_CPLUSPLUS_LANG >= 202002L
+#define Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX20 constexpr
+#else
+#define Y_ABSL_INTERNAL_CONSTEXPR_SINCE_CXX20
+#endif
+
 // Y_ABSL_INTERNAL_EMSCRIPTEN_VERSION combines Emscripten's three version macros
 // into an integer that can be compared against.
 #ifdef Y_ABSL_INTERNAL_EMSCRIPTEN_VERSION
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/dynamic_annotations.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/dynamic_annotations.h
index 1f486bc97e..2621435b3b 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/dynamic_annotations.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/dynamic_annotations.h
@@ -252,25 +252,9 @@ Y_ABSL_INTERNAL_END_EXTERN_C
 
 #else  // !defined(Y_ABSL_HAVE_MEMORY_SANITIZER)
 
-// TODO(rogeeff): remove this branch
-#ifdef Y_ABSL_HAVE_THREAD_SANITIZER
-#define Y_ABSL_ANNOTATE_MEMORY_IS_INITIALIZED(address, size) \
-  do {                                                     \
-    (void)(address);                                       \
-    (void)(size);                                          \
-  } while (0)
-#define Y_ABSL_ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size) \
-  do {                                                       \
-    (void)(address);                                         \
-    (void)(size);                                            \
-  } while (0)
-#else
-
 #define Y_ABSL_ANNOTATE_MEMORY_IS_INITIALIZED(address, size)    // empty
 #define Y_ABSL_ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size)  // empty
 
-#endif
-
 #endif  // Y_ABSL_HAVE_MEMORY_SANITIZER
 
 // -------------------------------------------------------------------------
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/nullability_impl.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/nullability_impl.h
index 17cd15fc17..aa5d374aa3 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/nullability_impl.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/nullability_impl.h
@@ -19,10 +19,11 @@
 #include <type_traits>
 
 #include "y_absl/base/attributes.h"
+#include "y_absl/base/config.h"
 #include "y_absl/meta/type_traits.h"
 
 namespace y_absl {
-
+Y_ABSL_NAMESPACE_BEGIN
 namespace nullability_internal {
 
 // `IsNullabilityCompatible` checks whether its first argument is a class
@@ -101,6 +102,7 @@ using NullabilityUnknownImpl
     = T;
 
 }  // namespace nullability_internal
+Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
 
 #endif  // Y_ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/poison.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/poison.cc
new file mode 100644
index 0000000000..10d608a942
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/poison.cc
@@ -0,0 +1,84 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "y_absl/base/internal/poison.h"
+
+#include <cstdlib>
+
+#include "y_absl/base/config.h"
+#include "y_absl/base/internal/direct_mmap.h"
+
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+
+#if defined(Y_ABSL_HAVE_ADDRESS_SANITIZER)
+#include <sanitizer/asan_interface.h>
+#elif defined(Y_ABSL_HAVE_MEMORY_SANITIZER)
+#include <sanitizer/msan_interface.h>
+#elif defined(Y_ABSL_HAVE_MMAP)
+#include <sys/mman.h>
+#endif
+
+#if defined(_WIN32)
+#include <windows.h>
+#endif
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace base_internal {
+
+namespace {
+
+size_t GetPageSize() {
+#ifdef _WIN32
+  SYSTEM_INFO system_info;
+  GetSystemInfo(&system_info);
+  return system_info.dwPageSize;
+#elif defined(__wasm__) || defined(__asmjs__) || defined(__hexagon__)
+  return getpagesize();
+#else
+  return static_cast<size_t>(sysconf(_SC_PAGESIZE));
+#endif
+}
+
+}  // namespace
+
+void* InitializePoisonedPointerInternal() {
+  const size_t block_size = GetPageSize();
+#if defined(Y_ABSL_HAVE_ADDRESS_SANITIZER)
+  void* data = malloc(block_size);
+  ASAN_POISON_MEMORY_REGION(data, block_size);
+#elif defined(Y_ABSL_HAVE_MEMORY_SANITIZER)
+  void* data = malloc(block_size);
+  __msan_poison(data, block_size);
+#elif defined(Y_ABSL_HAVE_MMAP)
+  void* data = DirectMmap(nullptr, block_size, PROT_NONE,
+                          MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (data == MAP_FAILED) return GetBadPointerInternal();
+#elif defined(_WIN32)
+  void* data = VirtualAlloc(nullptr, block_size, MEM_RESERVE | MEM_COMMIT,
+                            PAGE_NOACCESS);
+  if (data == nullptr) return GetBadPointerInternal();
+#else
+  return GetBadPointerInternal();
+#endif
+  // Return the middle of the block so that dereferences before and after the
+  // pointer will both crash.
+  return static_cast<char*>(data) + block_size / 2;
+}
+
+}  // namespace base_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/poison.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/poison.h
new file mode 100644
index 0000000000..4e3c7c0c33
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/poison.h
@@ -0,0 +1,59 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef Y_ABSL_BASE_INTERNAL_POISON_H_
+#define Y_ABSL_BASE_INTERNAL_POISON_H_
+
+#include <cstdint>
+
+#include "y_absl/base/config.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace base_internal {
+
+inline void* GetBadPointerInternal() {
+  // A likely bad pointer. Pointers are required to have high bits that are all
+  // zero or all one for certain 64-bit CPUs. This pointer value will hopefully
+  // cause a crash on dereference and also be clearly recognizable as invalid.
+  constexpr uint64_t kBadPtr = 0xBAD0BAD0BAD0BAD0;
+  auto ret = reinterpret_cast<void*>(static_cast<uintptr_t>(kBadPtr));
+#ifndef _MSC_VER  // MSVC doesn't support inline asm with `volatile`.
+  // Try to prevent the compiler from optimizing out the undefined behavior.
+  asm volatile("" : : "r"(ret) :);  // NOLINT
+#endif
+  return ret;
+}
+
+void* InitializePoisonedPointerInternal();
+
+inline void* get_poisoned_pointer() {
+#if defined(NDEBUG) && !defined(Y_ABSL_HAVE_ADDRESS_SANITIZER) && \
+    !defined(Y_ABSL_HAVE_MEMORY_SANITIZER)
+  // In optimized non-sanitized builds, avoid the function-local static because
+  // of the codegen and runtime cost.
+  return GetBadPointerInternal();
+#else
+  // Non-optimized builds may use more robust implementation. Note that we can't
+  // use a static global because Chromium doesn't allow non-constinit globals.
+  static void* ptr = InitializePoisonedPointerInternal();
+  return ptr;
+#endif
+}
+
+}  // namespace base_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_BASE_INTERNAL_POISON_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/spinlock.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/spinlock.h
index b2e0ee8bbc..aedfdd30b0 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/spinlock.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/spinlock.h
@@ -53,7 +53,7 @@ namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
 namespace base_internal {
 
-class Y_ABSL_LOCKABLE SpinLock {
+class Y_ABSL_LOCKABLE Y_ABSL_ATTRIBUTE_WARN_UNUSED SpinLock {
  public:
   SpinLock() : lockword_(kSpinLockCooperative) {
     Y_ABSL_TSAN_MUTEX_CREATE(this, __tsan_mutex_not_static);
@@ -89,7 +89,8 @@ class Y_ABSL_LOCKABLE SpinLock {
   // acquisition was successful.  If the lock was not acquired, false is
   // returned.  If this SpinLock is free at the time of the call, TryLock
   // will return true with high probability.
-  inline bool TryLock() Y_ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
+  Y_ABSL_MUST_USE_RESULT inline bool TryLock()
+      Y_ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
     Y_ABSL_TSAN_MUTEX_PRE_LOCK(this, __tsan_mutex_try_lock);
     bool res = TryLockImpl();
     Y_ABSL_TSAN_MUTEX_POST_LOCK(
@@ -120,7 +121,7 @@ class Y_ABSL_LOCKABLE SpinLock {
   // Determine if the lock is held.  When the lock is held by the invoking
   // thread, true will always be returned. Intended to be used as
   // CHECK(lock.IsHeld()).
-  inline bool IsHeld() const {
+  Y_ABSL_MUST_USE_RESULT inline bool IsHeld() const {
     return (lockword_.load(std::memory_order_relaxed) & kSpinLockHeld) != 0;
   }
 
@@ -202,6 +203,15 @@ class Y_ABSL_LOCKABLE SpinLock {
 
 // Corresponding locker object that arranges to acquire a spinlock for
 // the duration of a C++ scope.
+//
+// TODO(b/176172494): Use only [[nodiscard]] when baseline is raised.
+// TODO(b/6695610): Remove forward declaration when #ifdef is no longer needed.
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(nodiscard)
+class [[nodiscard]] SpinLockHolder;
+#else
+class Y_ABSL_MUST_USE_RESULT Y_ABSL_ATTRIBUTE_TRIVIAL_ABI SpinLockHolder;
+#endif
+
 class Y_ABSL_SCOPED_LOCKABLE SpinLockHolder {
  public:
   inline explicit SpinLockHolder(SpinLock* l) Y_ABSL_EXCLUSIVE_LOCK_FUNCTION(l)
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock.cc
index afd1a8b110..eed845ff0f 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock.cc
@@ -121,18 +121,6 @@ double UnscaledCycleClock::Frequency() {
   return aarch64_timer_frequency;
 }
 
-#elif defined(__riscv)
-
-int64_t UnscaledCycleClock::Now() {
-  int64_t virtual_timer_value;
-  asm volatile("rdcycle %0" : "=r"(virtual_timer_value));
-  return virtual_timer_value;
-}
-
-double UnscaledCycleClock::Frequency() {
-  return base_internal::NominalCPUFrequency();
-}
-
 #elif defined(_M_IX86) || defined(_M_X64)
 
 #pragma intrinsic(__rdtsc)
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock_config.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock_config.h
index 5ea8eac335..80cf455a43 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock_config.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/internal/unscaledcycleclock_config.h
@@ -21,8 +21,8 @@
 
 // The following platforms have an implementation of a hardware counter.
 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
-    defined(__powerpc__) || defined(__ppc__) || defined(__riscv) ||     \
-    defined(_M_IX86) || (defined(_M_X64) && !defined(_M_ARM64EC))
+    defined(__powerpc__) || defined(__ppc__) || defined(_M_IX86) ||     \
+    (defined(_M_X64) && !defined(_M_ARM64EC))
 #define Y_ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION 1
 #else
 #define Y_ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION 0
@@ -53,8 +53,8 @@
 #if Y_ABSL_USE_UNSCALED_CYCLECLOCK
 // This macro can be used to test if UnscaledCycleClock::Frequency()
 // is NominalCPUFrequency() on a particular platform.
-#if (defined(__i386__) || defined(__x86_64__) || defined(__riscv) || \
-     defined(_M_IX86) || defined(_M_X64))
+#if (defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || \
+     defined(_M_X64))
 #define Y_ABSL_INTERNAL_UNSCALED_CYCLECLOCK_FREQUENCY_IS_CPU_FREQUENCY
 #endif
 #endif
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/macros.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/macros.h
index e343701084..62aab25111 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/macros.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/macros.h
@@ -138,4 +138,52 @@ Y_ABSL_NAMESPACE_END
 #define Y_ABSL_INTERNAL_RETHROW do {} while (false)
 #endif  // Y_ABSL_HAVE_EXCEPTIONS
 
+// Y_ABSL_DEPRECATE_AND_INLINE()
+//
+// Marks a function or type alias as deprecated and tags it to be picked up for
+// automated refactoring by go/cpp-inliner. It can added to inline function
+// definitions or type aliases. It should only be used within a header file. It
+// differs from `Y_ABSL_DEPRECATED` in the following ways:
+//
+// 1. New uses of the function or type will be discouraged via Tricorder
+//    warnings.
+// 2. If enabled via `METADATA`, automated changes will be sent out inlining the
+//    functions's body or replacing the type where it is used.
+//
+// For example:
+//
+// Y_ABSL_DEPRECATE_AND_INLINE() inline int OldFunc(int x) {
+//   return NewFunc(x, 0);
+// }
+//
+// will mark `OldFunc` as deprecated, and the go/cpp-inliner service will
+// replace calls to `OldFunc(x)` with calls to `NewFunc(x, 0)`. Once all calls
+// to `OldFunc` have been replaced, `OldFunc` can be deleted.
+//
+// See go/cpp-inliner for more information.
+//
+// Note: go/cpp-inliner is Google-internal service for automated refactoring.
+// While open-source users do not have access to this service, the macro is
+// provided for compatibility, and so that users receive deprecation warnings.
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(deprecated) && \
+    Y_ABSL_HAVE_CPP_ATTRIBUTE(clang::annotate)
+#define Y_ABSL_DEPRECATE_AND_INLINE() [[deprecated, clang::annotate("inline-me")]]
+#elif Y_ABSL_HAVE_CPP_ATTRIBUTE(deprecated)
+#define Y_ABSL_DEPRECATE_AND_INLINE() [[deprecated]]
+#else
+#define Y_ABSL_DEPRECATE_AND_INLINE()
+#endif
+
+// Requires the compiler to prove that the size of the given object is at least
+// the expected amount.
+#if Y_ABSL_HAVE_ATTRIBUTE(diagnose_if) && Y_ABSL_HAVE_BUILTIN(__builtin_object_size)
+#define Y_ABSL_INTERNAL_NEED_MIN_SIZE(Obj, N)                     \
+  __attribute__((diagnose_if(__builtin_object_size(Obj, 0) < N, \
+                             "object size provably too small "  \
+                             "(this would corrupt memory)",     \
+                             "error")))
+#else
+#define Y_ABSL_INTERNAL_NEED_MIN_SIZE(Obj, N)
+#endif
+
 #endif  // Y_ABSL_BASE_MACROS_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/no_destructor.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/no_destructor.h
index 03dff922c6..2e01b93a68 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/no_destructor.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/no_destructor.h
@@ -21,14 +21,13 @@
 // such an object survives during program exit (and can be safely accessed at
 // any time).
 //
-// Objects of such type, if constructed safely and under the right conditions,
-// provide two main benefits over other alternatives:
-//
-//   * Global objects not normally allowed due to concerns of destruction order
-//     (i.e. no "complex globals") can be safely allowed, provided that such
-//     objects can be constant initialized.
-//   * Function scope static objects can be optimized to avoid heap allocation,
-//     pointer chasing, and allow lazy construction.
+// y_absl::NoDestructor<T> is useful when when a variable has static storage
+// duration but its type has a non-trivial destructor. Global constructors are
+// not recommended because of the C++'s static initialization order fiasco (See
+// https://en.cppreference.com/w/cpp/language/siof). Global destructors are not
+// allowed due to similar concerns about destruction ordering. Using
+// y_absl::NoDestructor<T> as a function-local static prevents both of these
+// issues.
 //
 // See below for complete details.
 
@@ -41,6 +40,7 @@
 #include <utility>
 
 #include "y_absl/base/config.h"
+#include "y_absl/base/nullability.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
@@ -49,8 +49,8 @@ Y_ABSL_NAMESPACE_BEGIN
 //
 // NoDestructor<T> is a wrapper around an object of type T that behaves as an
 // object of type T but never calls T's destructor. NoDestructor<T> makes it
-// safer and/or more efficient to use such objects in static storage contexts:
-// as global or function scope static variables.
+// safer and/or more efficient to use such objects in static storage contexts,
+// ideally as function scope static variables.
 //
 // An instance of y_absl::NoDestructor<T> has similar type semantics to an
 // instance of T:
@@ -61,9 +61,6 @@ Y_ABSL_NAMESPACE_BEGIN
 //   `->`, `*`, and `get()`.
 //   (Note that `const NoDestructor<T>` works like a pointer to const `T`.)
 //
-// An object of type NoDestructor<T> should be defined in static storage:
-// as either a global static object, or as a function scope static variable.
-//
 // Additionally, NoDestructor<T> provides the following benefits:
 //
 // * Never calls T's destructor for the object
@@ -71,24 +68,7 @@ Y_ABSL_NAMESPACE_BEGIN
 //   lazily constructed.
 //
 // An object of type NoDestructor<T> is "trivially destructible" in the notion
-// that its destructor is never run. Provided that an object of this type can be
-// safely initialized and does not need to be cleaned up on program shutdown,
-// NoDestructor<T> allows you to define global static variables, since Google's
-// C++ style guide ban on such objects doesn't apply to objects that are
-// trivially destructible.
-//
-// Usage as Global Static Variables
-//
-// NoDestructor<T> allows declaration of a global object with a non-trivial
-// constructor in static storage without needing to add a destructor.
-// However, such objects still need to worry about initialization order, so
-// such objects should be const initialized:
-//
-//    // Global or namespace scope.
-//    Y_ABSL_CONST_INIT y_absl::NoDestructor<MyRegistry> reg{"foo", "bar", 8008};
-//
-// Note that if your object already has a trivial destructor, you don't need to
-// use NoDestructor<T>.
+// that its destructor is never run.
 //
 // Usage as Function Scope Static Variables
 //
@@ -114,6 +94,21 @@ Y_ABSL_NAMESPACE_BEGIN
 //     return *x;
 //   }
 //
+// Usage as Global Static Variables
+//
+// NoDestructor<T> allows declaration of a global object of type T that has a
+// non-trivial destructor since its destructor is never run. However, such
+// objects still need to worry about initialization order, so such use is not
+// recommended, strongly discouraged by the Google C++ Style Guide, and outright
+// banned in Chromium.
+// See https://google.github.io/styleguide/cppguide.html#Static_and_Global_Variables
+//
+//    // Global or namespace scope.
+//    y_absl::NoDestructor<MyRegistry> reg{"foo", "bar", 8008};
+//
+// Note that if your object already has a trivial destructor, you don't need to
+// use NoDestructor<T>.
+//
 template <typename T>
 class NoDestructor {
  public:
@@ -140,11 +135,11 @@ class NoDestructor {
   // Pretend to be a smart pointer to T with deep constness.
   // Never returns a null pointer.
   T& operator*() { return *get(); }
-  T* operator->() { return get(); }
-  T* get() { return impl_.get(); }
+  y_absl::Nonnull<T*> operator->() { return get(); }
+  y_absl::Nonnull<T*> get() { return impl_.get(); }
   const T& operator*() const { return *get(); }
-  const T* operator->() const { return get(); }
-  const T* get() const { return impl_.get(); }
+  y_absl::Nonnull<const T*> operator->() const { return get(); }
+  y_absl::Nonnull<const T*> get() const { return impl_.get(); }
 
  private:
   class DirectImpl {
@@ -152,8 +147,8 @@ class NoDestructor {
     template <typename... Args>
     explicit constexpr DirectImpl(Args&&... args)
         : value_(std::forward<Args>(args)...) {}
-    const T* get() const { return &value_; }
-    T* get() { return &value_; }
+    y_absl::Nonnull<const T*> get() const { return &value_; }
+    y_absl::Nonnull<T*> get() { return &value_; }
 
    private:
     T value_;
@@ -165,14 +160,14 @@ class NoDestructor {
     explicit PlacementImpl(Args&&... args) {
       new (&space_) T(std::forward<Args>(args)...);
     }
-    const T* get() const {
+    y_absl::Nonnull<const T*> get() const {
       return Launder(reinterpret_cast<const T*>(&space_));
     }
-    T* get() { return Launder(reinterpret_cast<T*>(&space_)); }
+    y_absl::Nonnull<T*> get() { return Launder(reinterpret_cast<T*>(&space_)); }
 
    private:
     template <typename P>
-    static P* Launder(P* p) {
+    static y_absl::Nonnull<P*> Launder(y_absl::Nonnull<P*> p) {
 #if defined(__cpp_lib_launder) && __cpp_lib_launder >= 201606L
       return std::launder(p);
 #elif Y_ABSL_HAVE_BUILTIN(__builtin_launder)
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/nullability.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/nullability.h
index 4930eb7ac5..cd5b21ac37 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/nullability.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/nullability.h
@@ -128,9 +128,17 @@
 //
 // By default, nullability annotations are applicable to raw and smart
 // pointers. User-defined types can indicate compatibility with nullability
-// annotations by providing an `absl_nullability_compatible` nested type. The
-// actual definition of this inner type is not relevant as it is used merely as
-// a marker. It is common to use a using declaration of
+// annotations by adding the Y_ABSL_NULLABILITY_COMPATIBLE attribute.
+//
+// // Example:
+// struct Y_ABSL_NULLABILITY_COMPATIBLE MyPtr {
+//   ...
+// };
+//
+// Note: For the time being, nullability-compatible classes should additionally
+// be marked with an `absl_nullability_compatible` nested type (this will soon
+// be deprecated). The actual definition of this inner type is not relevant as
+// it is used merely as a marker. It is common to use a using declaration of
 // `absl_nullability_compatible` set to void.
 //
 // // Example:
@@ -150,14 +158,16 @@
 #ifndef Y_ABSL_BASE_NULLABILITY_H_
 #define Y_ABSL_BASE_NULLABILITY_H_
 
+#include "y_absl/base/config.h"
 #include "y_absl/base/internal/nullability_impl.h"
 
 namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
 
 // y_absl::Nonnull
 //
 // The indicated pointer is never null. It is the responsibility of the provider
-// of this pointer across an API boundary to ensure that the pointer is never be
+// of this pointer across an API boundary to ensure that the pointer is never
 // set to null. Consumers of this pointer across an API boundary may safely
 // dereference the pointer.
 //
@@ -198,9 +208,9 @@ using Nullable = nullability_internal::NullableImpl<T>;
 // migrated into one of the above two nullability states: `Nonnull<T>` or
 //  `Nullable<T>`.
 //
-// NOTE: Because this annotation is the global default state, pointers without
-// any annotation are assumed to have "unknown" semantics. This assumption is
-// designed to minimize churn and reduce clutter within the codebase.
+// NOTE: Because this annotation is the global default state, unannotated
+// pointers are assumed to have "unknown" semantics. This assumption is designed
+// to minimize churn and reduce clutter within the codebase.
 //
 // Example:
 //
@@ -219,6 +229,22 @@ using Nullable = nullability_internal::NullableImpl<T>;
 template <typename T>
 using NullabilityUnknown = nullability_internal::NullabilityUnknownImpl<T>;
 
+Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
 
+// Y_ABSL_NULLABILITY_COMPATIBLE
+//
+// Indicates that a class is compatible with nullability annotations.
+//
+// For example:
+//
+// struct Y_ABSL_NULLABILITY_COMPATIBLE MyPtr {
+//   ...
+// };
+#if Y_ABSL_HAVE_FEATURE(nullability_on_classes)
+#define Y_ABSL_NULLABILITY_COMPATIBLE _Nullable
+#else
+#define Y_ABSL_NULLABILITY_COMPATIBLE
+#endif
+
 #endif  // Y_ABSL_BASE_NULLABILITY_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/optimization.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/optimization.h
index 2fdcacfd72..b977c63e43 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/optimization.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/optimization.h
@@ -18,12 +18,23 @@
 // -----------------------------------------------------------------------------
 //
 // This header file defines portable macros for performance optimization.
+//
+// This header is included in both C++ code and legacy C code and thus must
+// remain compatible with both C and C++. C compatibility will be removed if
+// the legacy code is removed or converted to C++. Do not include this header in
+// new code that requires C compatibility or assume C compatibility will remain
+// indefinitely.
 
 #ifndef Y_ABSL_BASE_OPTIMIZATION_H_
 #define Y_ABSL_BASE_OPTIMIZATION_H_
 
 #include <assert.h>
 
+#ifdef __cplusplus
+// Included for std::unreachable()
+#include <utility>
+#endif  // __cplusplus
+
 #include "y_absl/base/config.h"
 #include "y_absl/base/options.h"
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/options.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/options.h
index 84f6d4df44..7f39f26075 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/options.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/options.h
@@ -226,7 +226,7 @@
 // allowed.
 
 #define Y_ABSL_OPTION_USE_INLINE_NAMESPACE 1
-#define Y_ABSL_OPTION_INLINE_NAMESPACE_NAME lts_y_20240116
+#define Y_ABSL_OPTION_INLINE_NAMESPACE_NAME lts_y_20240722
 
 // Y_ABSL_OPTION_HARDENED
 //
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/prefetch.h b/contrib/restricted/abseil-cpp-tstring/y_absl/base/prefetch.h
index 53f25bbd06..fe1103e441 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/prefetch.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/prefetch.h
@@ -129,7 +129,7 @@ void PrefetchToLocalCacheNta(const void* addr);
 //
 //  void* Arena::Allocate(size_t size) {
 //    void* ptr = AllocateBlock(size);
-//    y_absl::PrefetchToLocalCacheForWrite(p);
+//    y_absl::PrefetchToLocalCacheForWrite(ptr);
 //    return ptr;
 //  }
 //
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/base/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/base/ya.make
index 7f1a35bfcf..ca91a4610e 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/base/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/base/ya.make
@@ -19,6 +19,7 @@ NO_COMPILER_WARNINGS()
 SRCS(
     internal/cycleclock.cc
     internal/low_level_alloc.cc
+    internal/poison.cc
     internal/raw_logging.cc
     internal/scoped_set_env.cc
     internal/spinlock.cc
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_map.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_map.h
index c71b6402a7..a24278b56d 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_map.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_map.h
@@ -26,21 +26,24 @@
 //
 // In most cases, your default choice for a hash map should be a map of type
 // `flat_hash_map`.
+//
+// `flat_hash_map` is not exception-safe.
 
 #ifndef Y_ABSL_CONTAINER_FLAT_HASH_MAP_H_
 #define Y_ABSL_CONTAINER_FLAT_HASH_MAP_H_
 
 #include <cstddef>
-#include <new>
+#include <memory>
 #include <type_traits>
 #include <utility>
 
 #include "y_absl/algorithm/container.h"
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/macros.h"
+#include "y_absl/container/hash_container_defaults.h"
 #include "y_absl/container/internal/container_memory.h"
-#include "y_absl/container/internal/hash_function_defaults.h"  // IWYU pragma: export
 #include "y_absl/container/internal/raw_hash_map.h"  // IWYU pragma: export
-#include "y_absl/memory/memory.h"
+#include "y_absl/meta/type_traits.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
@@ -62,7 +65,7 @@ struct FlatHashMapPolicy;
 // * Requires values that are MoveConstructible
 // * Supports heterogeneous lookup, through `find()`, `operator[]()` and
 //   `insert()`, provided that the map is provided a compatible heterogeneous
-//   hashing function and equality operator.
+//   hashing function and equality operator. See below for details.
 // * Invalidates any references and pointers to elements within the table after
 //   `rehash()` and when the table is moved.
 // * Contains a `capacity()` member function indicating the number of element
@@ -80,6 +83,19 @@ struct FlatHashMapPolicy;
 // libraries (e.g. .dll, .so) is unsupported due to way `y_absl::Hash` values may
 // be randomized across dynamically loaded libraries.
 //
+// To achieve heterogeneous lookup for custom types either `Hash` and `Eq` type
+// parameters can be used or `T` should have public inner types
+// `absl_container_hash` and (optionally) `absl_container_eq`. In either case,
+// `typename Hash::is_transparent` and `typename Eq::is_transparent` should be
+// well-formed. Both types are basically functors:
+// * `Hash` should support `size_t operator()(U val) const` that returns a hash
+// for the given `val`.
+// * `Eq` should support `bool operator()(U lhs, V rhs) const` that returns true
+// if `lhs` is equal to `rhs`.
+//
+// In most cases `T` needs only to provide the `absl_container_hash`. In this
+// case `std::equal_to<void>` will be used instead of `eq` part.
+//
 // NOTE: A `flat_hash_map` stores its value types directly inside its
 // implementation array to avoid memory indirection. Because a `flat_hash_map`
 // is designed to move data when rehashed, map values will not retain pointer
@@ -106,13 +122,13 @@ struct FlatHashMapPolicy;
 //  if (result != ducks.end()) {
 //    std::cout << "Result: " << result->second << std::endl;
 //  }
-template <class K, class V,
-          class Hash = y_absl::container_internal::hash_default_hash<K>,
-          class Eq = y_absl::container_internal::hash_default_eq<K>,
+template <class K, class V, class Hash = DefaultHashContainerHash<K>,
+          class Eq = DefaultHashContainerEq<K>,
           class Allocator = std::allocator<std::pair<const K, V>>>
-class flat_hash_map : public y_absl::container_internal::raw_hash_map<
-                          y_absl::container_internal::FlatHashMapPolicy<K, V>,
-                          Hash, Eq, Allocator> {
+class Y_ABSL_INTERNAL_ATTRIBUTE_OWNER flat_hash_map
+    : public y_absl::container_internal::raw_hash_map<
+          y_absl::container_internal::FlatHashMapPolicy<K, V>, Hash, Eq,
+          Allocator> {
   using Base = typename flat_hash_map::raw_hash_map;
 
  public:
@@ -560,6 +576,38 @@ typename flat_hash_map<K, V, H, E, A>::size_type erase_if(
 
 namespace container_internal {
 
+// c_for_each_fast(flat_hash_map<>, Function)
+//
+// Container-based version of the <algorithm> `std::for_each()` function to
+// apply a function to a container's elements.
+// There is no guarantees on the order of the function calls.
+// Erasure and/or insertion of elements in the function is not allowed.
+template <typename K, typename V, typename H, typename E, typename A,
+          typename Function>
+decay_t<Function> c_for_each_fast(const flat_hash_map<K, V, H, E, A>& c,
+                                  Function&& f) {
+  container_internal::ForEach(f, &c);
+  return f;
+}
+template <typename K, typename V, typename H, typename E, typename A,
+          typename Function>
+decay_t<Function> c_for_each_fast(flat_hash_map<K, V, H, E, A>& c,
+                                  Function&& f) {
+  container_internal::ForEach(f, &c);
+  return f;
+}
+template <typename K, typename V, typename H, typename E, typename A,
+          typename Function>
+decay_t<Function> c_for_each_fast(flat_hash_map<K, V, H, E, A>&& c,
+                                  Function&& f) {
+  container_internal::ForEach(f, &c);
+  return f;
+}
+
+}  // namespace container_internal
+
+namespace container_internal {
+
 template <class K, class V>
 struct FlatHashMapPolicy {
   using slot_policy = container_internal::map_slot_policy<K, V>;
@@ -573,9 +621,10 @@ struct FlatHashMapPolicy {
     slot_policy::construct(alloc, slot, std::forward<Args>(args)...);
   }
 
+  // Returns std::true_type in case destroy is trivial.
   template <class Allocator>
-  static void destroy(Allocator* alloc, slot_type* slot) {
-    slot_policy::destroy(alloc, slot);
+  static auto destroy(Allocator* alloc, slot_type* slot) {
+    return slot_policy::destroy(alloc, slot);
   }
 
   template <class Allocator>
@@ -592,6 +641,13 @@ struct FlatHashMapPolicy {
                                                    std::forward<Args>(args)...);
   }
 
+  template <class Hash>
+  static constexpr HashSlotFn get_hash_slot_fn() {
+    return memory_internal::IsLayoutCompatible<K, V>::value
+               ? &TypeErasedApplyToSlotFn<Hash, K>
+               : nullptr;
+  }
+
   static size_t space_used(const slot_type*) { return 0; }
 
   static std::pair<const K, V>& element(slot_type* slot) { return slot->value; }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_set.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_set.h
index c9d414d6ca..3e92ef2cf1 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_set.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/flat_hash_set.h
@@ -26,18 +26,25 @@
 //
 // In most cases, your default choice for a hash set should be a set of type
 // `flat_hash_set`.
+//
+// `flat_hash_set` is not exception-safe.
+
 #ifndef Y_ABSL_CONTAINER_FLAT_HASH_SET_H_
 #define Y_ABSL_CONTAINER_FLAT_HASH_SET_H_
 
+#include <cstddef>
+#include <memory>
 #include <type_traits>
 #include <utility>
 
 #include "y_absl/algorithm/container.h"
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/macros.h"
+#include "y_absl/container/hash_container_defaults.h"
 #include "y_absl/container/internal/container_memory.h"
-#include "y_absl/container/internal/hash_function_defaults.h"  // IWYU pragma: export
 #include "y_absl/container/internal/raw_hash_set.h"  // IWYU pragma: export
 #include "y_absl/memory/memory.h"
+#include "y_absl/meta/type_traits.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
@@ -58,7 +65,7 @@ struct FlatHashSetPolicy;
 // * Requires keys that are CopyConstructible
 // * Supports heterogeneous lookup, through `find()` and `insert()`, provided
 //   that the set is provided a compatible heterogeneous hashing function and
-//   equality operator.
+//   equality operator. See below for details.
 // * Invalidates any references and pointers to elements within the table after
 //   `rehash()` and when the table is moved.
 // * Contains a `capacity()` member function indicating the number of element
@@ -76,6 +83,19 @@ struct FlatHashSetPolicy;
 // libraries (e.g. .dll, .so) is unsupported due to way `y_absl::Hash` values may
 // be randomized across dynamically loaded libraries.
 //
+// To achieve heterogeneous lookup for custom types either `Hash` and `Eq` type
+// parameters can be used or `T` should have public inner types
+// `absl_container_hash` and (optionally) `absl_container_eq`. In either case,
+// `typename Hash::is_transparent` and `typename Eq::is_transparent` should be
+// well-formed. Both types are basically functors:
+// * `Hash` should support `size_t operator()(U val) const` that returns a hash
+// for the given `val`.
+// * `Eq` should support `bool operator()(U lhs, V rhs) const` that returns true
+// if `lhs` is equal to `rhs`.
+//
+// In most cases `T` needs only to provide the `absl_container_hash`. In this
+// case `std::equal_to<void>` will be used instead of `eq` part.
+//
 // NOTE: A `flat_hash_set` stores its keys directly inside its implementation
 // array to avoid memory indirection. Because a `flat_hash_set` is designed to
 // move data when rehashed, set keys will not retain pointer stability. If you
@@ -99,10 +119,10 @@ struct FlatHashSetPolicy;
 //  if (ducks.contains("dewey")) {
 //    std::cout << "We found dewey!" << std::endl;
 //  }
-template <class T, class Hash = y_absl::container_internal::hash_default_hash<T>,
-          class Eq = y_absl::container_internal::hash_default_eq<T>,
+template <class T, class Hash = DefaultHashContainerHash<T>,
+          class Eq = DefaultHashContainerEq<T>,
           class Allocator = std::allocator<T>>
-class flat_hash_set
+class Y_ABSL_INTERNAL_ATTRIBUTE_OWNER flat_hash_set
     : public y_absl::container_internal::raw_hash_set<
           y_absl::container_internal::FlatHashSetPolicy<T>, Hash, Eq, Allocator> {
   using Base = typename flat_hash_set::raw_hash_set;
@@ -460,6 +480,33 @@ typename flat_hash_set<T, H, E, A>::size_type erase_if(
 
 namespace container_internal {
 
+// c_for_each_fast(flat_hash_set<>, Function)
+//
+// Container-based version of the <algorithm> `std::for_each()` function to
+// apply a function to a container's elements.
+// There is no guarantees on the order of the function calls.
+// Erasure and/or insertion of elements in the function is not allowed.
+template <typename T, typename H, typename E, typename A, typename Function>
+decay_t<Function> c_for_each_fast(const flat_hash_set<T, H, E, A>& c,
+                                  Function&& f) {
+  container_internal::ForEach(f, &c);
+  return f;
+}
+template <typename T, typename H, typename E, typename A, typename Function>
+decay_t<Function> c_for_each_fast(flat_hash_set<T, H, E, A>& c, Function&& f) {
+  container_internal::ForEach(f, &c);
+  return f;
+}
+template <typename T, typename H, typename E, typename A, typename Function>
+decay_t<Function> c_for_each_fast(flat_hash_set<T, H, E, A>&& c, Function&& f) {
+  container_internal::ForEach(f, &c);
+  return f;
+}
+
+}  // namespace container_internal
+
+namespace container_internal {
+
 template <class T>
 struct FlatHashSetPolicy {
   using slot_type = T;
@@ -473,9 +520,11 @@ struct FlatHashSetPolicy {
                                                  std::forward<Args>(args)...);
   }
 
+  // Return std::true_type in case destroy is trivial.
   template <class Allocator>
-  static void destroy(Allocator* alloc, slot_type* slot) {
+  static auto destroy(Allocator* alloc, slot_type* slot) {
     y_absl::allocator_traits<Allocator>::destroy(*alloc, slot);
+    return IsDestructionTrivial<Allocator, slot_type>();
   }
 
   static T& element(slot_type* slot) { return *slot; }
@@ -489,6 +538,11 @@ struct FlatHashSetPolicy {
   }
 
   static size_t space_used(const T*) { return 0; }
+
+  template <class Hash>
+  static constexpr HashSlotFn get_hash_slot_fn() {
+    return &TypeErasedApplyToSlotFn<Hash, T>;
+  }
 };
 }  // namespace container_internal
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/hash_container_defaults.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/hash_container_defaults.h
new file mode 100644
index 0000000000..8b234f9c90
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/hash_container_defaults.h
@@ -0,0 +1,45 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef Y_ABSL_CONTAINER_HASH_CONTAINER_DEFAULTS_H_
+#define Y_ABSL_CONTAINER_HASH_CONTAINER_DEFAULTS_H_
+
+#include "y_absl/base/config.h"
+#include "y_absl/container/internal/hash_function_defaults.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+
+// DefaultHashContainerHash is a convenience alias for the functor that is used
+// by default by Abseil hash-based (unordered) containers for hashing when
+// `Hash` type argument is not explicitly specified.
+//
+// This type alias can be used by generic code that wants to provide more
+// flexibility for defining underlying containers.
+template <typename T>
+using DefaultHashContainerHash = y_absl::container_internal::hash_default_hash<T>;
+
+// DefaultHashContainerEq is a convenience alias for the functor that is used by
+// default by Abseil hash-based (unordered) containers for equality check when
+// `Eq` type argument is not explicitly specified.
+//
+// This type alias can be used by generic code that wants to provide more
+// flexibility for defining underlying containers.
+template <typename T>
+using DefaultHashContainerEq = y_absl::container_internal::hash_default_eq<T>;
+
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_CONTAINER_HASH_CONTAINER_DEFAULTS_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/inlined_vector.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/inlined_vector.h
index f5df597aca..e2a782f460 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/inlined_vector.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/inlined_vector.h
@@ -775,7 +775,20 @@ class InlinedVector {
     Y_ABSL_HARDENING_ASSERT(pos >= begin());
     Y_ABSL_HARDENING_ASSERT(pos < end());
 
+    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102329#c2
+    // It appears that GCC thinks that since `pos` is a const pointer and may
+    // point to uninitialized memory at this point, a warning should be
+    // issued. But `pos` is actually only used to compute an array index to
+    // write to.
+#if !defined(__clang__) && defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#pragma GCC diagnostic ignored "-Wuninitialized"
+#endif
     return storage_.Erase(pos, pos + 1);
+#if !defined(__clang__) && defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
   }
 
   // Overload of `InlinedVector::erase(...)` that erases every element in the
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/common_policy_traits.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/common_policy_traits.h
index cdc3b07f32..cc73685dc8 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/common_policy_traits.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/common_policy_traits.h
@@ -45,9 +45,10 @@ struct common_policy_traits {
 
   // PRECONDITION: `slot` is INITIALIZED
   // POSTCONDITION: `slot` is UNINITIALIZED
+  // Returns std::true_type in case destroy is trivial.
   template <class Alloc>
-  static void destroy(Alloc* alloc, slot_type* slot) {
-    Policy::destroy(alloc, slot);
+  static auto destroy(Alloc* alloc, slot_type* slot) {
+    return Policy::destroy(alloc, slot);
   }
 
   // Transfers the `old_slot` to `new_slot`. Any memory allocated by the
@@ -63,7 +64,7 @@ struct common_policy_traits {
   //                UNINITIALIZED
   template <class Alloc>
   static void transfer(Alloc* alloc, slot_type* new_slot, slot_type* old_slot) {
-    transfer_impl(alloc, new_slot, old_slot, Rank0{});
+    transfer_impl(alloc, new_slot, old_slot, Rank2{});
   }
 
   // PRECONDITION: `slot` is INITIALIZED
@@ -82,23 +83,31 @@ struct common_policy_traits {
 
   static constexpr bool transfer_uses_memcpy() {
     return std::is_same<decltype(transfer_impl<std::allocator<char>>(
-                            nullptr, nullptr, nullptr, Rank0{})),
+                            nullptr, nullptr, nullptr, Rank2{})),
+                        std::true_type>::value;
+  }
+
+  // Returns true if destroy is trivial and can be omitted.
+  template <class Alloc>
+  static constexpr bool destroy_is_trivial() {
+    return std::is_same<decltype(destroy<Alloc>(nullptr, nullptr)),
                         std::true_type>::value;
   }
 
  private:
-  // To rank the overloads below for overload resolution. Rank0 is preferred.
-  struct Rank2 {};
-  struct Rank1 : Rank2 {};
-  struct Rank0 : Rank1 {};
+  // Use go/ranked-overloads for dispatching.
+  struct Rank0 {};
+  struct Rank1 : Rank0 {};
+  struct Rank2 : Rank1 {};
 
   // Use auto -> decltype as an enabler.
   // P::transfer returns std::true_type if transfer uses memcpy (e.g. in
   // node_slot_policy).
   template <class Alloc, class P = Policy>
   static auto transfer_impl(Alloc* alloc, slot_type* new_slot,
-                            slot_type* old_slot, Rank0)
-      -> decltype(P::transfer(alloc, new_slot, old_slot)) {
+                            slot_type* old_slot,
+                            Rank2) -> decltype(P::transfer(alloc, new_slot,
+                                                           old_slot)) {
     return P::transfer(alloc, new_slot, old_slot);
   }
 #if defined(__cpp_lib_launder) && __cpp_lib_launder >= 201606
@@ -121,7 +130,7 @@ struct common_policy_traits {
 
   template <class Alloc>
   static void transfer_impl(Alloc* alloc, slot_type* new_slot,
-                            slot_type* old_slot, Rank2) {
+                            slot_type* old_slot, Rank0) {
     construct(alloc, new_slot, std::move(element(old_slot)));
     destroy(alloc, old_slot);
   }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/compressed_tuple.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/compressed_tuple.h
index 6602a73088..6953a08d84 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/compressed_tuple.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/compressed_tuple.h
@@ -87,11 +87,11 @@ struct Storage {
   constexpr Storage() = default;
   template <typename V>
   explicit constexpr Storage(y_absl::in_place_t, V&& v)
-      : value(y_absl::forward<V>(v)) {}
+      : value(std::forward<V>(v)) {}
   constexpr const T& get() const& { return value; }
-  T& get() & { return value; }
-  constexpr const T&& get() const&& { return y_absl::move(*this).value; }
-  T&& get() && { return std::move(*this).value; }
+  constexpr T& get() & { return value; }
+  constexpr const T&& get() const&& { return std::move(*this).value; }
+  constexpr T&& get() && { return std::move(*this).value; }
 };
 
 template <typename T, size_t I>
@@ -99,13 +99,12 @@ struct Y_ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC Storage<T, I, true> : T {
   constexpr Storage() = default;
 
   template <typename V>
-  explicit constexpr Storage(y_absl::in_place_t, V&& v)
-      : T(y_absl::forward<V>(v)) {}
+  explicit constexpr Storage(y_absl::in_place_t, V&& v) : T(std::forward<V>(v)) {}
 
   constexpr const T& get() const& { return *this; }
-  T& get() & { return *this; }
-  constexpr const T&& get() const&& { return y_absl::move(*this); }
-  T&& get() && { return std::move(*this); }
+  constexpr T& get() & { return *this; }
+  constexpr const T&& get() const&& { return std::move(*this); }
+  constexpr T&& get() && { return std::move(*this); }
 };
 
 template <typename D, typename I, bool ShouldAnyUseBase>
@@ -123,7 +122,7 @@ struct Y_ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTupleImpl<
   constexpr CompressedTupleImpl() = default;
   template <typename... Vs>
   explicit constexpr CompressedTupleImpl(y_absl::in_place_t, Vs&&... args)
-      : Storage<Ts, I>(y_absl::in_place, y_absl::forward<Vs>(args))... {}
+      : Storage<Ts, I>(y_absl::in_place, std::forward<Vs>(args))... {}
   friend CompressedTuple<Ts...>;
 };
 
@@ -135,7 +134,7 @@ struct Y_ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTupleImpl<
   constexpr CompressedTupleImpl() = default;
   template <typename... Vs>
   explicit constexpr CompressedTupleImpl(y_absl::in_place_t, Vs&&... args)
-      : Storage<Ts, I, false>(y_absl::in_place, y_absl::forward<Vs>(args))... {}
+      : Storage<Ts, I, false>(y_absl::in_place, std::forward<Vs>(args))... {}
   friend CompressedTuple<Ts...>;
 };
 
@@ -234,11 +233,11 @@ class Y_ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTuple
                 bool> = true>
   explicit constexpr CompressedTuple(First&& first, Vs&&... base)
       : CompressedTuple::CompressedTupleImpl(y_absl::in_place,
-                                             y_absl::forward<First>(first),
-                                             y_absl::forward<Vs>(base)...) {}
+                                             std::forward<First>(first),
+                                             std::forward<Vs>(base)...) {}
 
   template <int I>
-  ElemT<I>& get() & {
+  constexpr ElemT<I>& get() & {
     return StorageT<I>::get();
   }
 
@@ -248,13 +247,13 @@ class Y_ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTuple
   }
 
   template <int I>
-  ElemT<I>&& get() && {
+  constexpr ElemT<I>&& get() && {
     return std::move(*this).StorageT<I>::get();
   }
 
   template <int I>
   constexpr const ElemT<I>&& get() const&& {
-    return y_absl::move(*this).StorageT<I>::get();
+    return std::move(*this).StorageT<I>::get();
   }
 };
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/container_memory.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/container_memory.h
index 82bb3ebde0..2a6281f541 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/container_memory.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/container_memory.h
@@ -68,6 +68,18 @@ void* Allocate(Alloc* alloc, size_t n) {
   return p;
 }
 
+// Returns true if the destruction of the value with given Allocator will be
+// trivial.
+template <class Allocator, class ValueType>
+constexpr auto IsDestructionTrivial() {
+  constexpr bool result =
+      std::is_trivially_destructible<ValueType>::value &&
+      std::is_same<typename y_absl::allocator_traits<
+                       Allocator>::template rebind_alloc<char>,
+                   std::allocator<char>>::value;
+  return std::integral_constant<bool, result>();
+}
+
 // The pointer must have been previously obtained by calling
 // Allocate<Alignment>(alloc, n).
 template <size_t Alignment, class Alloc>
@@ -414,12 +426,13 @@ struct map_slot_policy {
   }
 
   template <class Allocator>
-  static void destroy(Allocator* alloc, slot_type* slot) {
+  static auto destroy(Allocator* alloc, slot_type* slot) {
     if (kMutableKeys::value) {
       y_absl::allocator_traits<Allocator>::destroy(*alloc, &slot->mutable_value);
     } else {
       y_absl::allocator_traits<Allocator>::destroy(*alloc, &slot->value);
     }
+    return IsDestructionTrivial<Allocator, value_type>();
   }
 
   template <class Allocator>
@@ -451,6 +464,26 @@ struct map_slot_policy {
   }
 };
 
+// Type erased function for computing hash of the slot.
+using HashSlotFn = size_t (*)(const void* hash_fn, void* slot);
+
+// Type erased function to apply `Fn` to data inside of the `slot`.
+// The data is expected to have type `T`.
+template <class Fn, class T>
+size_t TypeErasedApplyToSlotFn(const void* fn, void* slot) {
+  const auto* f = static_cast<const Fn*>(fn);
+  return (*f)(*static_cast<const T*>(slot));
+}
+
+// Type erased function to apply `Fn` to data inside of the `*slot_ptr`.
+// The data is expected to have type `T`.
+template <class Fn, class T>
+size_t TypeErasedDerefAndApplyToSlotFn(const void* fn, void* slot_ptr) {
+  const auto* f = static_cast<const Fn*>(fn);
+  const T* slot = *static_cast<const T**>(slot_ptr);
+  return (*f)(*slot);
+}
+
 }  // namespace container_internal
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_function_defaults.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_function_defaults.h
index 98e3a9449b..bb4a0ddddf 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_function_defaults.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_function_defaults.h
@@ -45,14 +45,16 @@
 #ifndef Y_ABSL_CONTAINER_INTERNAL_HASH_FUNCTION_DEFAULTS_H_
 #define Y_ABSL_CONTAINER_INTERNAL_HASH_FUNCTION_DEFAULTS_H_
 
-#include <stdint.h>
 #include <cstddef>
+#include <functional>
 #include <memory>
 #include <util/generic/string.h>
 #include <type_traits>
 
 #include "y_absl/base/config.h"
+#include "y_absl/container/internal/common.h"
 #include "y_absl/hash/hash.h"
+#include "y_absl/meta/type_traits.h"
 #include "y_absl/strings/cord.h"
 #include "y_absl/strings/string_view.h"
 
@@ -188,6 +190,71 @@ struct HashEq<std::unique_ptr<T, D>> : HashEq<T*> {};
 template <class T>
 struct HashEq<std::shared_ptr<T>> : HashEq<T*> {};
 
+template <typename T, typename E = void>
+struct HasAbslContainerHash : std::false_type {};
+
+template <typename T>
+struct HasAbslContainerHash<T, y_absl::void_t<typename T::absl_container_hash>>
+    : std::true_type {};
+
+template <typename T, typename E = void>
+struct HasAbslContainerEq : std::false_type {};
+
+template <typename T>
+struct HasAbslContainerEq<T, y_absl::void_t<typename T::absl_container_eq>>
+    : std::true_type {};
+
+template <typename T, typename E = void>
+struct AbslContainerEq {
+  using type = std::equal_to<>;
+};
+
+template <typename T>
+struct AbslContainerEq<
+    T, typename std::enable_if_t<HasAbslContainerEq<T>::value>> {
+  using type = typename T::absl_container_eq;
+};
+
+template <typename T, typename E = void>
+struct AbslContainerHash {
+  using type = void;
+};
+
+template <typename T>
+struct AbslContainerHash<
+    T, typename std::enable_if_t<HasAbslContainerHash<T>::value>> {
+  using type = typename T::absl_container_hash;
+};
+
+// HashEq specialization for user types that provide `absl_container_hash` and
+// (optionally) `absl_container_eq`. This specialization allows user types to
+// provide heterogeneous lookup without requiring to explicitly specify Hash/Eq
+// type arguments in unordered Abseil containers.
+//
+// Both `absl_container_hash` and `absl_container_eq` should be transparent
+// (have inner is_transparent type). While there is no technical reason to
+// restrict to transparent-only types, there is also no feasible use case when
+// it shouldn't be transparent - it is easier to relax the requirement later if
+// such a case arises rather than restricting it.
+//
+// If type provides only `absl_container_hash` then `eq` part will be
+// `std::equal_to<void>`.
+//
+// User types are not allowed to provide only a `Eq` part as there is no
+// feasible use case for this behavior - if Hash should be a default one then Eq
+// should be an equivalent to the `std::equal_to<T>`.
+template <typename T>
+struct HashEq<T, typename std::enable_if_t<HasAbslContainerHash<T>::value>> {
+  using Hash = typename AbslContainerHash<T>::type;
+  using Eq = typename AbslContainerEq<T>::type;
+  static_assert(IsTransparent<Hash>::value,
+                "absl_container_hash must be transparent. To achieve it add a "
+                "`using is_transparent = void;` clause to this type.");
+  static_assert(IsTransparent<Eq>::value,
+                "absl_container_eq must be transparent. To achieve it add a "
+                "`using is_transparent = void;` clause to this type.");
+};
+
 // This header's visibility is restricted.  If you need to access the default
 // hasher please use the container's ::hasher alias instead.
 //
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_policy_traits.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_policy_traits.h
index cf60b63e5f..4eee196983 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_policy_traits.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hash_policy_traits.h
@@ -148,6 +148,56 @@ struct hash_policy_traits : common_policy_traits<Policy> {
   static auto value(T* elem) -> decltype(P::value(elem)) {
     return P::value(elem);
   }
+
+  using HashSlotFn = size_t (*)(const void* hash_fn, void* slot);
+
+  template <class Hash>
+  static constexpr HashSlotFn get_hash_slot_fn() {
+// get_hash_slot_fn may return nullptr to signal that non type erased function
+// should be used. GCC warns against comparing function address with nullptr.
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic push
+// silent error: the address of * will never be NULL [-Werror=address]
+#pragma GCC diagnostic ignored "-Waddress"
+#endif
+    return Policy::template get_hash_slot_fn<Hash>() == nullptr
+               ? &hash_slot_fn_non_type_erased<Hash>
+               : Policy::template get_hash_slot_fn<Hash>();
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
+  }
+
+  // Whether small object optimization is enabled. True by default.
+  static constexpr bool soo_enabled() { return soo_enabled_impl(Rank1{}); }
+
+ private:
+  template <class Hash>
+  struct HashElement {
+    template <class K, class... Args>
+    size_t operator()(const K& key, Args&&...) const {
+      return h(key);
+    }
+    const Hash& h;
+  };
+
+  template <class Hash>
+  static size_t hash_slot_fn_non_type_erased(const void* hash_fn, void* slot) {
+    return Policy::apply(HashElement<Hash>{*static_cast<const Hash*>(hash_fn)},
+                         Policy::element(static_cast<slot_type*>(slot)));
+  }
+
+  // Use go/ranked-overloads for dispatching. Rank1 is preferred.
+  struct Rank0 {};
+  struct Rank1 : Rank0 {};
+
+  // Use auto -> decltype as an enabler.
+  template <class P = Policy>
+  static constexpr auto soo_enabled_impl(Rank1) -> decltype(P::soo_enabled()) {
+    return P::soo_enabled();
+  }
+
+  static constexpr bool soo_enabled_impl(Rank0) { return true; }
 };
 
 }  // namespace container_internal
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.cc
index e6369d913d..cb3bd879f8 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.cc
@@ -18,12 +18,18 @@
 #include <atomic>
 #include <cassert>
 #include <cmath>
+#include <cstddef>
+#include <cstdint>
 #include <functional>
 #include <limits>
 
 #include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
+#include "y_absl/base/internal/per_thread_tls.h"
 #include "y_absl/base/internal/raw_logging.h"
+#include "y_absl/base/macros.h"
+#include "y_absl/base/no_destructor.h"
+#include "y_absl/base/optimization.h"
 #include "y_absl/debugging/stacktrace.h"
 #include "y_absl/memory/memory.h"
 #include "y_absl/profiling/internal/exponential_biased.h"
@@ -64,7 +70,7 @@ Y_ABSL_PER_THREAD_TLS_KEYWORD SamplingState global_next_sample = {0, 0};
 #endif  // defined(Y_ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
 
 HashtablezSampler& GlobalHashtablezSampler() {
-  static auto* sampler = new HashtablezSampler();
+  static y_absl::NoDestructor<HashtablezSampler> sampler;
   return *sampler;
 }
 
@@ -72,7 +78,10 @@ HashtablezInfo::HashtablezInfo() = default;
 HashtablezInfo::~HashtablezInfo() = default;
 
 void HashtablezInfo::PrepareForSampling(int64_t stride,
-                                        size_t inline_element_size_value) {
+                                        size_t inline_element_size_value,
+                                        size_t key_size_value,
+                                        size_t value_size_value,
+                                        uint16_t soo_capacity_value) {
   capacity.store(0, std::memory_order_relaxed);
   size.store(0, std::memory_order_relaxed);
   num_erases.store(0, std::memory_order_relaxed);
@@ -92,6 +101,9 @@ void HashtablezInfo::PrepareForSampling(int64_t stride,
   depth = y_absl::GetStackTrace(stack, HashtablezInfo::kMaxStackDepth,
                               /* skip_count= */ 0);
   inline_element_size = inline_element_size_value;
+  key_size = key_size_value;
+  value_size = value_size_value;
+  soo_capacity = soo_capacity_value;
 }
 
 static bool ShouldForceSampling() {
@@ -115,12 +127,13 @@ static bool ShouldForceSampling() {
 }
 
 HashtablezInfo* SampleSlow(SamplingState& next_sample,
-                           size_t inline_element_size) {
+                           size_t inline_element_size, size_t key_size,
+                           size_t value_size, uint16_t soo_capacity) {
   if (Y_ABSL_PREDICT_FALSE(ShouldForceSampling())) {
     next_sample.next_sample = 1;
     const int64_t old_stride = exchange(next_sample.sample_stride, 1);
-    HashtablezInfo* result =
-        GlobalHashtablezSampler().Register(old_stride, inline_element_size);
+    HashtablezInfo* result = GlobalHashtablezSampler().Register(
+        old_stride, inline_element_size, key_size, value_size, soo_capacity);
     return result;
   }
 
@@ -150,10 +163,12 @@ HashtablezInfo* SampleSlow(SamplingState& next_sample,
   // that case.
   if (first) {
     if (Y_ABSL_PREDICT_TRUE(--next_sample.next_sample > 0)) return nullptr;
-    return SampleSlow(next_sample, inline_element_size);
+    return SampleSlow(next_sample, inline_element_size, key_size, value_size,
+                      soo_capacity);
   }
 
-  return GlobalHashtablezSampler().Register(old_stride, inline_element_size);
+  return GlobalHashtablezSampler().Register(old_stride, inline_element_size,
+                                            key_size, value_size, soo_capacity);
 #endif
 }
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.h
index 32f64a22a6..7c2cba672d 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/hashtablez_sampler.h
@@ -40,15 +40,20 @@
 #define Y_ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_
 
 #include <atomic>
+#include <cstddef>
+#include <cstdint>
 #include <functional>
 #include <memory>
 #include <vector>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/per_thread_tls.h"
 #include "y_absl/base/optimization.h"
+#include "y_absl/base/thread_annotations.h"
 #include "y_absl/profiling/internal/sample_recorder.h"
 #include "y_absl/synchronization/mutex.h"
+#include "y_absl/time/time.h"
 #include "y_absl/utility/utility.h"
 
 namespace y_absl {
@@ -67,7 +72,9 @@ struct HashtablezInfo : public profiling_internal::Sample<HashtablezInfo> {
 
   // Puts the object into a clean state, fills in the logically `const` members,
   // blocking for any readers that are currently sampling the object.
-  void PrepareForSampling(int64_t stride, size_t inline_element_size_value)
+  void PrepareForSampling(int64_t stride, size_t inline_element_size_value,
+                          size_t key_size, size_t value_size,
+                          uint16_t soo_capacity_value)
       Y_ABSL_EXCLUSIVE_LOCKS_REQUIRED(init_mu);
 
   // These fields are mutated by the various Record* APIs and need to be
@@ -91,8 +98,15 @@ struct HashtablezInfo : public profiling_internal::Sample<HashtablezInfo> {
   static constexpr int kMaxStackDepth = 64;
   y_absl::Time create_time;
   int32_t depth;
+  // The SOO capacity for this table in elements (not bytes). Note that sampled
+  // tables are never SOO because we need to store the infoz handle on the heap.
+  // Tables that would be SOO if not sampled should have: soo_capacity > 0 &&
+  // size <= soo_capacity && max_reserve <= soo_capacity.
+  uint16_t soo_capacity;
   void* stack[kMaxStackDepth];
-  size_t inline_element_size;  // How big is the slot?
+  size_t inline_element_size;  // How big is the slot in bytes?
+  size_t key_size;             // sizeof(key_type)
+  size_t value_size;           // sizeof(value_type)
 };
 
 void RecordRehashSlow(HashtablezInfo* info, size_t total_probe_length);
@@ -117,7 +131,8 @@ struct SamplingState {
 };
 
 HashtablezInfo* SampleSlow(SamplingState& next_sample,
-                           size_t inline_element_size);
+                           size_t inline_element_size, size_t key_size,
+                           size_t value_size, uint16_t soo_capacity);
 void UnsampleSlow(HashtablezInfo* info);
 
 #if defined(Y_ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
@@ -204,16 +219,19 @@ class HashtablezInfoHandle {
 extern Y_ABSL_PER_THREAD_TLS_KEYWORD SamplingState global_next_sample;
 #endif  // defined(Y_ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
 
-// Returns an RAII sampling handle that manages registration and unregistation
-// with the global sampler.
+// Returns a sampling handle.
 inline HashtablezInfoHandle Sample(
-    size_t inline_element_size Y_ABSL_ATTRIBUTE_UNUSED) {
+    Y_ABSL_ATTRIBUTE_UNUSED size_t inline_element_size,
+    Y_ABSL_ATTRIBUTE_UNUSED size_t key_size,
+    Y_ABSL_ATTRIBUTE_UNUSED size_t value_size,
+    Y_ABSL_ATTRIBUTE_UNUSED uint16_t soo_capacity) {
 #if defined(Y_ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
   if (Y_ABSL_PREDICT_TRUE(--global_next_sample.next_sample > 0)) {
     return HashtablezInfoHandle(nullptr);
   }
-  return HashtablezInfoHandle(
-      SampleSlow(global_next_sample, inline_element_size));
+  return HashtablezInfoHandle(SampleSlow(global_next_sample,
+                                         inline_element_size, key_size,
+                                         value_size, soo_capacity));
 #else
   return HashtablezInfoHandle(nullptr);
 #endif  // !Y_ABSL_PER_THREAD_TLS
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/inlined_vector.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/inlined_vector.h
index 67fffc4f79..a56a777462 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/inlined_vector.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/inlined_vector.h
@@ -27,6 +27,7 @@
 
 #include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
+#include "y_absl/base/internal/identity.h"
 #include "y_absl/base/macros.h"
 #include "y_absl/container/internal/compressed_tuple.h"
 #include "y_absl/memory/memory.h"
@@ -82,16 +83,6 @@ using IsMoveAssignOk = std::is_move_assignable<ValueType<A>>;
 template <typename A>
 using IsSwapOk = y_absl::type_traits_internal::IsSwappable<ValueType<A>>;
 
-template <typename T>
-struct TypeIdentity {
-  using type = T;
-};
-
-// Used for function arguments in template functions to prevent ADL by forcing
-// callers to explicitly specify the template parameter.
-template <typename T>
-using NoTypeDeduction = typename TypeIdentity<T>::type;
-
 template <typename A, bool IsTriviallyDestructible =
                           y_absl::is_trivially_destructible<ValueType<A>>::value>
 struct DestroyAdapter;
@@ -139,7 +130,7 @@ struct MallocAdapter {
 };
 
 template <typename A, typename ValueAdapter>
-void ConstructElements(NoTypeDeduction<A>& allocator,
+void ConstructElements(y_absl::internal::type_identity_t<A>& allocator,
                        Pointer<A> construct_first, ValueAdapter& values,
                        SizeType<A> construct_size) {
   for (SizeType<A> i = 0; i < construct_size; ++i) {
@@ -322,14 +313,13 @@ class Storage {
 
   // The policy to be used specifically when swapping inlined elements.
   using SwapInlinedElementsPolicy = y_absl::conditional_t<
-      // Fast path: if the value type can be trivially move constructed/assigned
-      // and destroyed, and we know the allocator doesn't do anything fancy,
-      // then it's safe for us to simply swap the bytes in the inline storage.
-      // It's as if we had move-constructed a temporary vector, move-assigned
-      // one to the other, then move-assigned the first from the temporary.
-      y_absl::conjunction<y_absl::is_trivially_move_constructible<ValueType<A>>,
-                        y_absl::is_trivially_move_assignable<ValueType<A>>,
-                        y_absl::is_trivially_destructible<ValueType<A>>,
+      // Fast path: if the value type can be trivially relocated, and we
+      // know the allocator doesn't do anything fancy, then it's safe for us
+      // to simply swap the bytes in the inline storage. It's as if we had
+      // relocated the first vector's elements into temporary storage,
+      // relocated the second's elements into the (now-empty) first's,
+      // and then relocated from temporary storage into the second.
+      y_absl::conjunction<y_absl::is_trivially_relocatable<ValueType<A>>,
                         std::is_same<A, std::allocator<ValueType<A>>>>::value,
       MemcpyPolicy,
       y_absl::conditional_t<IsSwapOk<A>::value, ElementwiseSwapPolicy,
@@ -624,8 +614,8 @@ void Storage<T, N, A>::InitFrom(const Storage& other) {
 
 template <typename T, size_t N, typename A>
 template <typename ValueAdapter>
-auto Storage<T, N, A>::Initialize(ValueAdapter values, SizeType<A> new_size)
-    -> void {
+auto Storage<T, N, A>::Initialize(ValueAdapter values,
+                                  SizeType<A> new_size) -> void {
   // Only callable from constructors!
   Y_ABSL_HARDENING_ASSERT(!GetIsAllocated());
   Y_ABSL_HARDENING_ASSERT(GetSize() == 0);
@@ -656,8 +646,8 @@ auto Storage<T, N, A>::Initialize(ValueAdapter values, SizeType<A> new_size)
 
 template <typename T, size_t N, typename A>
 template <typename ValueAdapter>
-auto Storage<T, N, A>::Assign(ValueAdapter values, SizeType<A> new_size)
-    -> void {
+auto Storage<T, N, A>::Assign(ValueAdapter values,
+                              SizeType<A> new_size) -> void {
   StorageView<A> storage_view = MakeStorageView();
 
   AllocationTransaction<A> allocation_tx(GetAllocator());
@@ -699,8 +689,8 @@ auto Storage<T, N, A>::Assign(ValueAdapter values, SizeType<A> new_size)
 
 template <typename T, size_t N, typename A>
 template <typename ValueAdapter>
-auto Storage<T, N, A>::Resize(ValueAdapter values, SizeType<A> new_size)
-    -> void {
+auto Storage<T, N, A>::Resize(ValueAdapter values,
+                              SizeType<A> new_size) -> void {
   StorageView<A> storage_view = MakeStorageView();
   Pointer<A> const base = storage_view.data;
   const SizeType<A> size = storage_view.size;
@@ -885,8 +875,8 @@ auto Storage<T, N, A>::EmplaceBackSlow(Args&&... args) -> Reference<A> {
 }
 
 template <typename T, size_t N, typename A>
-auto Storage<T, N, A>::Erase(ConstIterator<A> from, ConstIterator<A> to)
-    -> Iterator<A> {
+auto Storage<T, N, A>::Erase(ConstIterator<A> from,
+                             ConstIterator<A> to) -> Iterator<A> {
   StorageView<A> storage_view = MakeStorageView();
 
   auto erase_size = static_cast<SizeType<A>>(std::distance(from, to));
@@ -894,16 +884,30 @@ auto Storage<T, N, A>::Erase(ConstIterator<A> from, ConstIterator<A> to)
       std::distance(ConstIterator<A>(storage_view.data), from));
   SizeType<A> erase_end_index = erase_index + erase_size;
 
-  IteratorValueAdapter<A, MoveIterator<A>> move_values(
-      MoveIterator<A>(storage_view.data + erase_end_index));
-
-  AssignElements<A>(storage_view.data + erase_index, move_values,
-                    storage_view.size - erase_end_index);
+  // Fast path: if the value type is trivially relocatable and we know
+  // the allocator doesn't do anything fancy, then we know it is legal for us to
+  // simply destroy the elements in the "erasure window" (which cannot throw)
+  // and then memcpy downward to close the window.
+  if (y_absl::is_trivially_relocatable<ValueType<A>>::value &&
+      std::is_nothrow_destructible<ValueType<A>>::value &&
+      std::is_same<A, std::allocator<ValueType<A>>>::value) {
+    DestroyAdapter<A>::DestroyElements(
+        GetAllocator(), storage_view.data + erase_index, erase_size);
+    std::memmove(
+        reinterpret_cast<char*>(storage_view.data + erase_index),
+        reinterpret_cast<const char*>(storage_view.data + erase_end_index),
+        (storage_view.size - erase_end_index) * sizeof(ValueType<A>));
+  } else {
+    IteratorValueAdapter<A, MoveIterator<A>> move_values(
+        MoveIterator<A>(storage_view.data + erase_end_index));
 
-  DestroyAdapter<A>::DestroyElements(
-      GetAllocator(), storage_view.data + (storage_view.size - erase_size),
-      erase_size);
+    AssignElements<A>(storage_view.data + erase_index, move_values,
+                      storage_view.size - erase_end_index);
 
+    DestroyAdapter<A>::DestroyElements(
+        GetAllocator(), storage_view.data + (storage_view.size - erase_size),
+        erase_size);
+  }
   SubtractSize(erase_size);
   return Iterator<A>(storage_view.data + erase_index);
 }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_map.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_map.h
index d442b3189e..8f0050a84c 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_map.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_map.h
@@ -198,22 +198,24 @@ class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> {
   std::pair<iterator, bool> insert_or_assign_impl(K&& k, V&& v)
       Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
     auto res = this->find_or_prepare_insert(k);
-    if (res.second)
+    if (res.second) {
       this->emplace_at(res.first, std::forward<K>(k), std::forward<V>(v));
-    else
-      Policy::value(&*this->iterator_at(res.first)) = std::forward<V>(v);
-    return {this->iterator_at(res.first), res.second};
+    } else {
+      Policy::value(&*res.first) = std::forward<V>(v);
+    }
+    return res;
   }
 
   template <class K = key_type, class... Args>
   std::pair<iterator, bool> try_emplace_impl(K&& k, Args&&... args)
       Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
     auto res = this->find_or_prepare_insert(k);
-    if (res.second)
+    if (res.second) {
       this->emplace_at(res.first, std::piecewise_construct,
                        std::forward_as_tuple(std::forward<K>(k)),
                        std::forward_as_tuple(std::forward<Args>(args)...));
-    return {this->iterator_at(res.first), res.second};
+    }
+    return res;
   }
 };
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.cc
index bb19ecf63e..8517e51ba7 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.cc
@@ -23,19 +23,24 @@
 #include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/dynamic_annotations.h"
+#include "y_absl/base/internal/endian.h"
+#include "y_absl/base/optimization.h"
 #include "y_absl/container/internal/container_memory.h"
+#include "y_absl/container/internal/hashtablez_sampler.h"
 #include "y_absl/hash/hash.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
 namespace container_internal {
 
-// We have space for `growth_left` before a single block of control bytes. A
+// Represents a control byte corresponding to a full slot with arbitrary hash.
+constexpr ctrl_t ZeroCtrlT() { return static_cast<ctrl_t>(0); }
+
+// We have space for `growth_info` before a single block of control bytes. A
 // single block of empty control bytes for tables without any slots allocated.
 // This enables removing a branch in the hot path of find(). In order to ensure
 // that the control bytes are aligned to 16, we have 16 bytes before the control
-// bytes even though growth_left only needs 8.
-constexpr ctrl_t ZeroCtrlT() { return static_cast<ctrl_t>(0); }
+// bytes even though growth_info only needs 8.
 alignas(16) Y_ABSL_CONST_INIT Y_ABSL_DLL const ctrl_t kEmptyGroup[32] = {
     ZeroCtrlT(),       ZeroCtrlT(),    ZeroCtrlT(),    ZeroCtrlT(),
     ZeroCtrlT(),       ZeroCtrlT(),    ZeroCtrlT(),    ZeroCtrlT(),
@@ -46,6 +51,18 @@ alignas(16) Y_ABSL_CONST_INIT Y_ABSL_DLL const ctrl_t kEmptyGroup[32] = {
     ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
     ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty};
 
+// We need one full byte followed by a sentinel byte for iterator::operator++ to
+// work. We have a full group after kSentinel to be safe (in case operator++ is
+// changed to read a full group).
+Y_ABSL_CONST_INIT Y_ABSL_DLL const ctrl_t kSooControl[17] = {
+    ZeroCtrlT(),    ctrl_t::kSentinel, ZeroCtrlT(),    ctrl_t::kEmpty,
+    ctrl_t::kEmpty, ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty, ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty, ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty};
+static_assert(NumControlBytes(SooCapacity()) <= 17,
+              "kSooControl capacity too small");
+
 #ifdef Y_ABSL_INTERNAL_NEED_REDUNDANT_CONSTEXPR_DECL
 constexpr size_t Group::kWidth;
 #endif
@@ -104,10 +121,25 @@ bool CommonFieldsGenerationInfoEnabled::should_rehash_for_bug_detection_on_move(
   return ShouldRehashForBugDetection(ctrl, capacity);
 }
 
-bool ShouldInsertBackwards(size_t hash, const ctrl_t* ctrl) {
+bool ShouldInsertBackwardsForDebug(size_t capacity, size_t hash,
+                                   const ctrl_t* ctrl) {
   // To avoid problems with weak hashes and single bit tests, we use % 13.
   // TODO(kfm,sbenza): revisit after we do unconditional mixing
-  return (H1(hash, ctrl) ^ RandomSeed()) % 13 > 6;
+  return !is_small(capacity) && (H1(hash, ctrl) ^ RandomSeed()) % 13 > 6;
+}
+
+size_t PrepareInsertAfterSoo(size_t hash, size_t slot_size,
+                             CommonFields& common) {
+  assert(common.capacity() == NextCapacity(SooCapacity()));
+  // After resize from capacity 1 to 3, we always have exactly the slot with
+  // index 1 occupied, so we need to insert either at index 0 or index 2.
+  assert(HashSetResizeHelper::SooSlotIndex() == 1);
+  PrepareInsertCommon(common);
+  const size_t offset = H1(hash, common.control()) & 2;
+  common.growth_info().OverwriteEmptyAsFull();
+  SetCtrlInSingleGroupTable(common, offset, H2(hash), slot_size);
+  common.infoz().RecordInsert(hash, /*distance_from_desired=*/0);
+  return offset;
 }
 
 void ConvertDeletedToEmptyAndFullToDeleted(ctrl_t* ctrl, size_t capacity) {
@@ -128,6 +160,8 @@ FindInfo find_first_non_full_outofline(const CommonFields& common,
   return find_first_non_full(common, hash);
 }
 
+namespace {
+
 // Returns the address of the slot just after slot assuming each slot has the
 // specified size.
 static inline void* NextSlot(void* slot, size_t slot_size) {
@@ -140,8 +174,22 @@ static inline void* PrevSlot(void* slot, size_t slot_size) {
   return reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(slot) - slot_size);
 }
 
+// Finds guaranteed to exists empty slot from the given position.
+// NOTE: this function is almost never triggered inside of the
+// DropDeletesWithoutResize, so we keep it simple.
+// The table is rather sparse, so empty slot will be found very quickly.
+size_t FindEmptySlot(size_t start, size_t end, const ctrl_t* ctrl) {
+  for (size_t i = start; i < end; ++i) {
+    if (IsEmpty(ctrl[i])) {
+      return i;
+    }
+  }
+  assert(false && "no empty slot");
+  return ~size_t{};
+}
+
 void DropDeletesWithoutResize(CommonFields& common,
-                              const PolicyFunctions& policy, void* tmp_space) {
+                              const PolicyFunctions& policy) {
   void* set = &common;
   void* slot_array = common.slot_array();
   const size_t capacity = common.capacity();
@@ -165,17 +213,28 @@ void DropDeletesWithoutResize(CommonFields& common,
   //       repeat procedure for current slot with moved from element (target)
   ctrl_t* ctrl = common.control();
   ConvertDeletedToEmptyAndFullToDeleted(ctrl, capacity);
+  const void* hash_fn = policy.hash_fn(common);
   auto hasher = policy.hash_slot;
   auto transfer = policy.transfer;
   const size_t slot_size = policy.slot_size;
 
   size_t total_probe_length = 0;
   void* slot_ptr = SlotAddress(slot_array, 0, slot_size);
+
+  // The index of an empty slot that can be used as temporary memory for
+  // the swap operation.
+  constexpr size_t kUnknownId = ~size_t{};
+  size_t tmp_space_id = kUnknownId;
+
   for (size_t i = 0; i != capacity;
        ++i, slot_ptr = NextSlot(slot_ptr, slot_size)) {
     assert(slot_ptr == SlotAddress(slot_array, i, slot_size));
+    if (IsEmpty(ctrl[i])) {
+      tmp_space_id = i;
+      continue;
+    }
     if (!IsDeleted(ctrl[i])) continue;
-    const size_t hash = (*hasher)(set, slot_ptr);
+    const size_t hash = (*hasher)(hash_fn, slot_ptr);
     const FindInfo target = find_first_non_full(common, hash);
     const size_t new_i = target.offset;
     total_probe_length += target.probe_length;
@@ -202,16 +261,26 @@ void DropDeletesWithoutResize(CommonFields& common,
       SetCtrl(common, new_i, H2(hash), slot_size);
       (*transfer)(set, new_slot_ptr, slot_ptr);
       SetCtrl(common, i, ctrl_t::kEmpty, slot_size);
+      // Initialize or change empty space id.
+      tmp_space_id = i;
     } else {
       assert(IsDeleted(ctrl[new_i]));
       SetCtrl(common, new_i, H2(hash), slot_size);
       // Until we are done rehashing, DELETED marks previously FULL slots.
 
+      if (tmp_space_id == kUnknownId) {
+        tmp_space_id = FindEmptySlot(i + 1, capacity, ctrl);
+      }
+      void* tmp_space = SlotAddress(slot_array, tmp_space_id, slot_size);
+      SanitizerUnpoisonMemoryRegion(tmp_space, slot_size);
+
       // Swap i and new_i elements.
       (*transfer)(set, tmp_space, new_slot_ptr);
       (*transfer)(set, new_slot_ptr, slot_ptr);
       (*transfer)(set, slot_ptr, tmp_space);
 
+      SanitizerPoisonMemoryRegion(tmp_space, slot_size);
+
       // repeat the processing of the ith slot
       --i;
       slot_ptr = PrevSlot(slot_ptr, slot_size);
@@ -238,6 +307,8 @@ static bool WasNeverFull(CommonFields& c, size_t index) {
              Group::kWidth;
 }
 
+}  // namespace
+
 void EraseMetaOnly(CommonFields& c, size_t index, size_t slot_size) {
   assert(IsFull(c.control()[index]) && "erasing a dangling iterator");
   c.decrement_size();
@@ -245,17 +316,19 @@ void EraseMetaOnly(CommonFields& c, size_t index, size_t slot_size) {
 
   if (WasNeverFull(c, index)) {
     SetCtrl(c, index, ctrl_t::kEmpty, slot_size);
-    c.set_growth_left(c.growth_left() + 1);
+    c.growth_info().OverwriteFullAsEmpty();
     return;
   }
 
+  c.growth_info().OverwriteFullAsDeleted();
   SetCtrl(c, index, ctrl_t::kDeleted, slot_size);
 }
 
 void ClearBackingArray(CommonFields& c, const PolicyFunctions& policy,
-                       bool reuse) {
+                       bool reuse, bool soo_enabled) {
   c.set_size(0);
   if (reuse) {
+    assert(!soo_enabled || c.capacity() > SooCapacity());
     ResetCtrl(c, policy.slot_size);
     ResetGrowthLeft(c);
     c.infoz().RecordStorageChanged(0, c.capacity());
@@ -263,118 +336,308 @@ void ClearBackingArray(CommonFields& c, const PolicyFunctions& policy,
     // We need to record infoz before calling dealloc, which will unregister
     // infoz.
     c.infoz().RecordClearedReservation();
-    c.infoz().RecordStorageChanged(0, 0);
+    c.infoz().RecordStorageChanged(0, soo_enabled ? SooCapacity() : 0);
     (*policy.dealloc)(c, policy);
-    c.set_control(EmptyGroup());
-    c.set_generation_ptr(EmptyGeneration());
-    c.set_slots(nullptr);
-    c.set_capacity(0);
+    c = soo_enabled ? CommonFields{soo_tag_t{}} : CommonFields{};
   }
 }
 
 void HashSetResizeHelper::GrowIntoSingleGroupShuffleControlBytes(
-    ctrl_t* new_ctrl, size_t new_capacity) const {
+    ctrl_t* __restrict new_ctrl, size_t new_capacity) const {
   assert(is_single_group(new_capacity));
   constexpr size_t kHalfWidth = Group::kWidth / 2;
+  constexpr size_t kQuarterWidth = Group::kWidth / 4;
   assert(old_capacity_ < kHalfWidth);
+  static_assert(sizeof(uint64_t) >= kHalfWidth,
+                "Group size is too large. The ctrl bytes for half a group must "
+                "fit into a uint64_t for this implementation.");
+  static_assert(sizeof(uint64_t) <= Group::kWidth,
+                "Group size is too small. The ctrl bytes for a group must "
+                "cover a uint64_t for this implementation.");
 
   const size_t half_old_capacity = old_capacity_ / 2;
 
   // NOTE: operations are done with compile time known size = kHalfWidth.
   // Compiler optimizes that into single ASM operation.
 
-  // Copy second half of bytes to the beginning.
-  // We potentially copy more bytes in order to have compile time known size.
-  // Mirrored bytes from the old_ctrl_ will also be copied.
-  // In case of old_capacity_ == 3, we will copy 1st element twice.
+  // Load the bytes from half_old_capacity + 1. This contains the last half of
+  // old_ctrl bytes, followed by the sentinel byte, and then the first half of
+  // the cloned bytes. This effectively shuffles the control bytes.
+  uint64_t copied_bytes = 0;
+  copied_bytes =
+      y_absl::little_endian::Load64(old_ctrl() + half_old_capacity + 1);
+
+  // We change the sentinel byte to kEmpty before storing to both the start of
+  // the new_ctrl, and past the end of the new_ctrl later for the new cloned
+  // bytes. Note that this is faster than setting the sentinel byte to kEmpty
+  // after the copy directly in new_ctrl because we are limited on store
+  // bandwidth.
+  constexpr uint64_t kEmptyXorSentinel =
+      static_cast<uint8_t>(ctrl_t::kEmpty) ^
+      static_cast<uint8_t>(ctrl_t::kSentinel);
+  const uint64_t mask_convert_old_sentinel_to_empty =
+      kEmptyXorSentinel << (half_old_capacity * 8);
+  copied_bytes ^= mask_convert_old_sentinel_to_empty;
+
+  // Copy second half of bytes to the beginning. This correctly sets the bytes
+  // [0, old_capacity]. We potentially copy more bytes in order to have compile
+  // time known size. Mirrored bytes from the old_ctrl() will also be copied. In
+  // case of old_capacity_ == 3, we will copy 1st element twice.
   // Examples:
+  // (old capacity = 1)
   // old_ctrl = 0S0EEEEEEE...
-  // new_ctrl = S0EEEEEEEE...
+  // new_ctrl = E0EEEEEE??...
   //
-  // old_ctrl = 01S01EEEEE...
-  // new_ctrl = 1S01EEEEEE...
+  // (old capacity = 3)
+  // old_ctrl = 012S012EEEEE...
+  // new_ctrl = 12E012EE????...
   //
+  // (old capacity = 7)
   // old_ctrl = 0123456S0123456EE...
-  // new_ctrl = 456S0123?????????...
-  std::memcpy(new_ctrl, old_ctrl_ + half_old_capacity + 1, kHalfWidth);
-  // Clean up copied kSentinel from old_ctrl.
-  new_ctrl[half_old_capacity] = ctrl_t::kEmpty;
-
-  // Clean up damaged or uninitialized bytes.
-
-  // Clean bytes after the intended size of the copy.
-  // Example:
-  // new_ctrl = 1E01EEEEEEE????
-  // *new_ctrl= 1E0EEEEEEEE????
-  // position      /
-  std::memset(new_ctrl + old_capacity_ + 1, static_cast<int8_t>(ctrl_t::kEmpty),
-              kHalfWidth);
-  // Clean non-mirrored bytes that are not initialized.
-  // For small old_capacity that may be inside of mirrored bytes zone.
+  // new_ctrl = 456E0123?????????...
+  y_absl::little_endian::Store64(new_ctrl, copied_bytes);
+
+  // Set the space [old_capacity + 1, new_capacity] to empty as these bytes will
+  // not be written again. This is safe because
+  // NumControlBytes = new_capacity + kWidth and new_capacity >=
+  // old_capacity+1.
   // Examples:
-  // new_ctrl = 1E0EEEEEEEE??????????....
-  // *new_ctrl= 1E0EEEEEEEEEEEEE?????....
-  // position           /
+  // (old_capacity = 3, new_capacity = 15)
+  // new_ctrl  = 12E012EE?????????????...??
+  // *new_ctrl = 12E0EEEEEEEEEEEEEEEE?...??
+  // position        /          S
   //
-  // new_ctrl = 456E0123???????????...
-  // *new_ctrl= 456E0123EEEEEEEE???...
-  // position           /
-  std::memset(new_ctrl + kHalfWidth, static_cast<int8_t>(ctrl_t::kEmpty),
-              kHalfWidth);
-  // Clean last mirrored bytes that are not initialized
-  // and will not be overwritten by mirroring.
+  // (old_capacity = 7, new_capacity = 15)
+  // new_ctrl  = 456E0123?????????????????...??
+  // *new_ctrl = 456E0123EEEEEEEEEEEEEEEE?...??
+  // position            /      S
+  std::memset(new_ctrl + old_capacity_ + 1, static_cast<int8_t>(ctrl_t::kEmpty),
+              Group::kWidth);
+
+  // Set the last kHalfWidth bytes to empty, to ensure the bytes all the way to
+  // the end are initialized.
   // Examples:
-  // new_ctrl = 1E0EEEEEEEEEEEEE????????
-  // *new_ctrl= 1E0EEEEEEEEEEEEEEEEEEEEE
-  // position           S       /
+  // new_ctrl  = 12E0EEEEEEEEEEEEEEEE?...???????
+  // *new_ctrl = 12E0EEEEEEEEEEEEEEEE???EEEEEEEE
+  // position                   S       /
   //
-  // new_ctrl = 456E0123EEEEEEEE???????????????
-  // *new_ctrl= 456E0123EEEEEEEE???????EEEEEEEE
-  // position                  S       /
-  std::memset(new_ctrl + new_capacity + kHalfWidth,
+  // new_ctrl  = 456E0123EEEEEEEEEEEEEEEE???????
+  // *new_ctrl = 456E0123EEEEEEEEEEEEEEEEEEEEEEE
+  // position                   S       /
+  std::memset(new_ctrl + NumControlBytes(new_capacity) - kHalfWidth,
               static_cast<int8_t>(ctrl_t::kEmpty), kHalfWidth);
 
-  // Create mirrored bytes. old_capacity_ < kHalfWidth
-  // Example:
-  // new_ctrl = 456E0123EEEEEEEE???????EEEEEEEE
-  // *new_ctrl= 456E0123EEEEEEEE456E0123EEEEEEE
-  // position                  S/
-  ctrl_t g[kHalfWidth];
-  std::memcpy(g, new_ctrl, kHalfWidth);
-  std::memcpy(new_ctrl + new_capacity + 1, g, kHalfWidth);
+  // Copy the first bytes to the end (starting at new_capacity +1) to set the
+  // cloned bytes. Note that we use the already copied bytes from old_ctrl here
+  // rather than copying from new_ctrl to avoid a Read-after-Write hazard, since
+  // new_ctrl was just written to. The first old_capacity-1 bytes are set
+  // correctly. Then there may be up to old_capacity bytes that need to be
+  // overwritten, and any remaining bytes will be correctly set to empty. This
+  // sets [new_capacity + 1, new_capacity +1 + old_capacity] correctly.
+  // Examples:
+  // new_ctrl  = 12E0EEEEEEEEEEEEEEEE?...???????
+  // *new_ctrl = 12E0EEEEEEEEEEEE12E012EEEEEEEEE
+  // position                   S/
+  //
+  // new_ctrl  = 456E0123EEEEEEEE?...???EEEEEEEE
+  // *new_ctrl = 456E0123EEEEEEEE456E0123EEEEEEE
+  // position                   S/
+  y_absl::little_endian::Store64(new_ctrl + new_capacity + 1, copied_bytes);
+
+  // Set The remaining bytes at the end past the cloned bytes to empty. The
+  // incorrectly set bytes are [new_capacity + old_capacity + 2,
+  // min(new_capacity + 1 + kHalfWidth, new_capacity + old_capacity + 2 +
+  // half_old_capacity)]. Taking the difference, we need to set min(kHalfWidth -
+  // (old_capacity + 1), half_old_capacity)]. Since old_capacity < kHalfWidth,
+  // half_old_capacity < kQuarterWidth, so we set kQuarterWidth beginning at
+  // new_capacity + old_capacity + 2 to kEmpty.
+  // Examples:
+  // new_ctrl  = 12E0EEEEEEEEEEEE12E012EEEEEEEEE
+  // *new_ctrl = 12E0EEEEEEEEEEEE12E0EEEEEEEEEEE
+  // position                   S    /
+  //
+  // new_ctrl  = 456E0123EEEEEEEE456E0123EEEEEEE
+  // *new_ctrl = 456E0123EEEEEEEE456E0123EEEEEEE (no change)
+  // position                   S        /
+  std::memset(new_ctrl + new_capacity + old_capacity_ + 2,
+              static_cast<int8_t>(ctrl_t::kEmpty), kQuarterWidth);
+
+  // Finally, we set the new sentinel byte.
+  new_ctrl[new_capacity] = ctrl_t::kSentinel;
+}
 
-  // Finally set sentinel to its place.
+void HashSetResizeHelper::InitControlBytesAfterSoo(ctrl_t* new_ctrl, ctrl_t h2,
+                                                   size_t new_capacity) {
+  assert(is_single_group(new_capacity));
+  std::memset(new_ctrl, static_cast<int8_t>(ctrl_t::kEmpty),
+              NumControlBytes(new_capacity));
+  assert(HashSetResizeHelper::SooSlotIndex() == 1);
+  // This allows us to avoid branching on had_soo_slot_.
+  assert(had_soo_slot_ || h2 == ctrl_t::kEmpty);
+  new_ctrl[1] = new_ctrl[new_capacity + 2] = h2;
   new_ctrl[new_capacity] = ctrl_t::kSentinel;
 }
 
 void HashSetResizeHelper::GrowIntoSingleGroupShuffleTransferableSlots(
-    void* old_slots, void* new_slots, size_t slot_size) const {
+    void* new_slots, size_t slot_size) const {
   assert(old_capacity_ > 0);
   const size_t half_old_capacity = old_capacity_ / 2;
 
-  SanitizerUnpoisonMemoryRegion(old_slots, slot_size * old_capacity_);
+  SanitizerUnpoisonMemoryRegion(old_slots(), slot_size * old_capacity_);
   std::memcpy(new_slots,
-              SlotAddress(old_slots, half_old_capacity + 1, slot_size),
+              SlotAddress(old_slots(), half_old_capacity + 1, slot_size),
               slot_size * half_old_capacity);
   std::memcpy(SlotAddress(new_slots, half_old_capacity + 1, slot_size),
-              old_slots, slot_size * (half_old_capacity + 1));
+              old_slots(), slot_size * (half_old_capacity + 1));
 }
 
 void HashSetResizeHelper::GrowSizeIntoSingleGroupTransferable(
-    CommonFields& c, void* old_slots, size_t slot_size) {
+    CommonFields& c, size_t slot_size) {
   assert(old_capacity_ < Group::kWidth / 2);
   assert(is_single_group(c.capacity()));
   assert(IsGrowingIntoSingleGroupApplicable(old_capacity_, c.capacity()));
 
   GrowIntoSingleGroupShuffleControlBytes(c.control(), c.capacity());
-  GrowIntoSingleGroupShuffleTransferableSlots(old_slots, c.slot_array(),
-                                              slot_size);
+  GrowIntoSingleGroupShuffleTransferableSlots(c.slot_array(), slot_size);
 
   // We poison since GrowIntoSingleGroupShuffleTransferableSlots
   // may leave empty slots unpoisoned.
   PoisonSingleGroupEmptySlots(c, slot_size);
 }
 
+void HashSetResizeHelper::TransferSlotAfterSoo(CommonFields& c,
+                                               size_t slot_size) {
+  assert(was_soo_);
+  assert(had_soo_slot_);
+  assert(is_single_group(c.capacity()));
+  std::memcpy(SlotAddress(c.slot_array(), SooSlotIndex(), slot_size),
+              old_soo_data(), slot_size);
+  PoisonSingleGroupEmptySlots(c, slot_size);
+}
+
+namespace {
+
+// Called whenever the table needs to vacate empty slots either by removing
+// tombstones via rehash or growth.
+Y_ABSL_ATTRIBUTE_NOINLINE
+FindInfo FindInsertPositionWithGrowthOrRehash(CommonFields& common, size_t hash,
+                                              const PolicyFunctions& policy) {
+  const size_t cap = common.capacity();
+  if (cap > Group::kWidth &&
+      // Do these calculations in 64-bit to avoid overflow.
+      common.size() * uint64_t{32} <= cap * uint64_t{25}) {
+    // Squash DELETED without growing if there is enough capacity.
+    //
+    // Rehash in place if the current size is <= 25/32 of capacity.
+    // Rationale for such a high factor: 1) DropDeletesWithoutResize() is
+    // faster than resize, and 2) it takes quite a bit of work to add
+    // tombstones.  In the worst case, seems to take approximately 4
+    // insert/erase pairs to create a single tombstone and so if we are
+    // rehashing because of tombstones, we can afford to rehash-in-place as
+    // long as we are reclaiming at least 1/8 the capacity without doing more
+    // than 2X the work.  (Where "work" is defined to be size() for rehashing
+    // or rehashing in place, and 1 for an insert or erase.)  But rehashing in
+    // place is faster per operation than inserting or even doubling the size
+    // of the table, so we actually afford to reclaim even less space from a
+    // resize-in-place.  The decision is to rehash in place if we can reclaim
+    // at about 1/8th of the usable capacity (specifically 3/28 of the
+    // capacity) which means that the total cost of rehashing will be a small
+    // fraction of the total work.
+    //
+    // Here is output of an experiment using the BM_CacheInSteadyState
+    // benchmark running the old case (where we rehash-in-place only if we can
+    // reclaim at least 7/16*capacity) vs. this code (which rehashes in place
+    // if we can recover 3/32*capacity).
+    //
+    // Note that although in the worst-case number of rehashes jumped up from
+    // 15 to 190, but the number of operations per second is almost the same.
+    //
+    // Abridged output of running BM_CacheInSteadyState benchmark from
+    // raw_hash_set_benchmark.   N is the number of insert/erase operations.
+    //
+    //      | OLD (recover >= 7/16        | NEW (recover >= 3/32)
+    // size |    N/s LoadFactor NRehashes |    N/s LoadFactor NRehashes
+    //  448 | 145284       0.44        18 | 140118       0.44        19
+    //  493 | 152546       0.24        11 | 151417       0.48        28
+    //  538 | 151439       0.26        11 | 151152       0.53        38
+    //  583 | 151765       0.28        11 | 150572       0.57        50
+    //  628 | 150241       0.31        11 | 150853       0.61        66
+    //  672 | 149602       0.33        12 | 150110       0.66        90
+    //  717 | 149998       0.35        12 | 149531       0.70       129
+    //  762 | 149836       0.37        13 | 148559       0.74       190
+    //  807 | 149736       0.39        14 | 151107       0.39        14
+    //  852 | 150204       0.42        15 | 151019       0.42        15
+    DropDeletesWithoutResize(common, policy);
+  } else {
+    // Otherwise grow the container.
+    policy.resize(common, NextCapacity(cap), HashtablezInfoHandle{});
+  }
+  // This function is typically called with tables containing deleted slots.
+  // The table will be big and `FindFirstNonFullAfterResize` will always
+  // fallback to `find_first_non_full`. So using `find_first_non_full` directly.
+  return find_first_non_full(common, hash);
+}
+
+}  // namespace
+
+const void* GetHashRefForEmptyHasher(const CommonFields& common) {
+  // Empty base optimization typically make the empty base class address to be
+  // the same as the first address of the derived class object.
+  // But we generally assume that for empty hasher we can return any valid
+  // pointer.
+  return &common;
+}
+
+size_t PrepareInsertNonSoo(CommonFields& common, size_t hash, FindInfo target,
+                           const PolicyFunctions& policy) {
+  // When there are no deleted slots in the table
+  // and growth_left is positive, we can insert at the first
+  // empty slot in the probe sequence (target).
+  const bool use_target_hint =
+      // Optimization is disabled when generations are enabled.
+      // We have to rehash even sparse tables randomly in such mode.
+      !SwisstableGenerationsEnabled() &&
+      common.growth_info().HasNoDeletedAndGrowthLeft();
+  if (Y_ABSL_PREDICT_FALSE(!use_target_hint)) {
+    // Notes about optimized mode when generations are disabled:
+    // We do not enter this branch if table has no deleted slots
+    // and growth_left is positive.
+    // We enter this branch in the following cases listed in decreasing
+    // frequency:
+    // 1. Table without deleted slots (>95% cases) that needs to be resized.
+    // 2. Table with deleted slots that has space for the inserting element.
+    // 3. Table with deleted slots that needs to be rehashed or resized.
+    if (Y_ABSL_PREDICT_TRUE(common.growth_info().HasNoGrowthLeftAndNoDeleted())) {
+      const size_t old_capacity = common.capacity();
+      policy.resize(common, NextCapacity(old_capacity), HashtablezInfoHandle{});
+      target = HashSetResizeHelper::FindFirstNonFullAfterResize(
+          common, old_capacity, hash);
+    } else {
+      // Note: the table may have no deleted slots here when generations
+      // are enabled.
+      const bool rehash_for_bug_detection =
+          common.should_rehash_for_bug_detection_on_insert();
+      if (rehash_for_bug_detection) {
+        // Move to a different heap allocation in order to detect bugs.
+        const size_t cap = common.capacity();
+        policy.resize(common,
+                      common.growth_left() > 0 ? cap : NextCapacity(cap),
+                      HashtablezInfoHandle{});
+      }
+      if (Y_ABSL_PREDICT_TRUE(common.growth_left() > 0)) {
+        target = find_first_non_full(common, hash);
+      } else {
+        target = FindInsertPositionWithGrowthOrRehash(common, hash, policy);
+      }
+    }
+  }
+  PrepareInsertCommon(common);
+  common.growth_info().OverwriteControlAsFull(common.control()[target.offset]);
+  SetCtrl(common, target.offset, H2(hash), policy.slot_size);
+  common.infoz().RecordInsert(hash, target.probe_length);
+  return target.offset;
+}
+
 }  // namespace container_internal
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.h b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.h
index eb2ef632c2..f3e9d12445 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/container/internal/raw_hash_set.h
@@ -80,7 +80,7 @@
 //     slot_type slots[capacity];
 //   };
 //
-// The length of this array is computed by `AllocSize()` below.
+// The length of this array is computed by `RawHashSetLayout::alloc_size` below.
 //
 // Control bytes (`ctrl_t`) are bytes (collected into groups of a
 // platform-specific size) that define the state of the corresponding slot in
@@ -100,6 +100,13 @@
 // Storing control bytes in a separate array also has beneficial cache effects,
 // since more logical slots will fit into a cache line.
 //
+// # Small Object Optimization (SOO)
+//
+// When the size/alignment of the value_type and the capacity of the table are
+// small, we enable small object optimization and store the values inline in
+// the raw_hash_set object. This optimization allows us to avoid
+// allocation/deallocation as well as cache/dTLB misses.
+//
 // # Hashing
 //
 // We compute two separate hashes, `H1` and `H2`, from the hash of an object.
@@ -233,9 +240,10 @@ namespace container_internal {
 
 #ifdef Y_ABSL_SWISSTABLE_ENABLE_GENERATIONS
 #error Y_ABSL_SWISSTABLE_ENABLE_GENERATIONS cannot be directly set
-#elif defined(Y_ABSL_HAVE_ADDRESS_SANITIZER) || \
-    defined(Y_ABSL_HAVE_HWADDRESS_SANITIZER) || \
-    defined(Y_ABSL_HAVE_MEMORY_SANITIZER)
+#elif (defined(Y_ABSL_HAVE_ADDRESS_SANITIZER) ||   \
+       defined(Y_ABSL_HAVE_HWADDRESS_SANITIZER) || \
+       defined(Y_ABSL_HAVE_MEMORY_SANITIZER)) &&   \
+    !defined(NDEBUG_SANITIZER)  // If defined, performance is important.
 // When compiled in sanitizer mode, we add generation integers to the backing
 // array and iterators. In the backing array, we store the generation between
 // the control bytes and the slots. When iterators are dereferenced, we assert
@@ -374,6 +382,9 @@ uint32_t TrailingZeros(T x) {
   return static_cast<uint32_t>(countr_zero(x));
 }
 
+// 8 bytes bitmask with most significant bit set for every byte.
+constexpr uint64_t kMsbs8Bytes = 0x8080808080808080ULL;
+
 // An abstract bitmask, such as that emitted by a SIMD instruction.
 //
 // Specifically, this type implements a simple bitset whose representation is
@@ -423,27 +434,35 @@ class NonIterableBitMask {
 // an ordinary 16-bit bitset occupying the low 16 bits of `mask`. When
 // `SignificantBits` is 8 and `Shift` is 3, abstract bits are represented as
 // the bytes `0x00` and `0x80`, and it occupies all 64 bits of the bitmask.
+// If NullifyBitsOnIteration is true (only allowed for Shift == 3),
+// non zero abstract bit is allowed to have additional bits
+// (e.g., `0xff`, `0x83` and `0x9c` are ok, but `0x6f` is not).
 //
 // For example:
 //   for (int i : BitMask<uint32_t, 16>(0b101)) -> yields 0, 2
 //   for (int i : BitMask<uint64_t, 8, 3>(0x0000000080800000)) -> yields 2, 3
-template <class T, int SignificantBits, int Shift = 0>
+template <class T, int SignificantBits, int Shift = 0,
+          bool NullifyBitsOnIteration = false>
 class BitMask : public NonIterableBitMask<T, SignificantBits, Shift> {
   using Base = NonIterableBitMask<T, SignificantBits, Shift>;
   static_assert(std::is_unsigned<T>::value, "");
   static_assert(Shift == 0 || Shift == 3, "");
+  static_assert(!NullifyBitsOnIteration || Shift == 3, "");
 
  public:
-  explicit BitMask(T mask) : Base(mask) {}
+  explicit BitMask(T mask) : Base(mask) {
+    if (Shift == 3 && !NullifyBitsOnIteration) {
+      assert(this->mask_ == (this->mask_ & kMsbs8Bytes));
+    }
+  }
   // BitMask is an iterator over the indices of its abstract bits.
   using value_type = int;
   using iterator = BitMask;
   using const_iterator = BitMask;
 
   BitMask& operator++() {
-    if (Shift == 3) {
-      constexpr uint64_t msbs = 0x8080808080808080ULL;
-      this->mask_ &= msbs;
+    if (Shift == 3 && NullifyBitsOnIteration) {
+      this->mask_ &= kMsbs8Bytes;
     }
     this->mask_ &= (this->mask_ - 1);
     return *this;
@@ -520,10 +539,24 @@ Y_ABSL_DLL extern const ctrl_t kEmptyGroup[32];
 // Returns a pointer to a control byte group that can be used by empty tables.
 inline ctrl_t* EmptyGroup() {
   // Const must be cast away here; no uses of this function will actually write
-  // to it, because it is only used for empty tables.
+  // to it because it is only used for empty tables.
   return const_cast<ctrl_t*>(kEmptyGroup + 16);
 }
 
+// For use in SOO iterators.
+// TODO(b/289225379): we could potentially get rid of this by adding an is_soo
+// bit in iterators. This would add branches but reduce cache misses.
+Y_ABSL_DLL extern const ctrl_t kSooControl[17];
+
+// Returns a pointer to a full byte followed by a sentinel byte.
+inline ctrl_t* SooControl() {
+  // Const must be cast away here; no uses of this function will actually write
+  // to it because it is only used for SOO iterators.
+  return const_cast<ctrl_t*>(kSooControl);
+}
+// Whether ctrl is from the SooControl array.
+inline bool IsSooControl(const ctrl_t* ctrl) { return ctrl == SooControl(); }
+
 // Returns a pointer to a generation to use for an empty hashtable.
 GenerationType* EmptyGeneration();
 
@@ -535,7 +568,37 @@ inline bool IsEmptyGeneration(const GenerationType* generation) {
 
 // Mixes a randomly generated per-process seed with `hash` and `ctrl` to
 // randomize insertion order within groups.
-bool ShouldInsertBackwards(size_t hash, const ctrl_t* ctrl);
+bool ShouldInsertBackwardsForDebug(size_t capacity, size_t hash,
+                                   const ctrl_t* ctrl);
+
+Y_ABSL_ATTRIBUTE_ALWAYS_INLINE inline bool ShouldInsertBackwards(
+    Y_ABSL_ATTRIBUTE_UNUSED size_t capacity, Y_ABSL_ATTRIBUTE_UNUSED size_t hash,
+    Y_ABSL_ATTRIBUTE_UNUSED const ctrl_t* ctrl) {
+#if defined(NDEBUG)
+  return false;
+#else
+  return ShouldInsertBackwardsForDebug(capacity, hash, ctrl);
+#endif
+}
+
+// Returns insert position for the given mask.
+// We want to add entropy even when ASLR is not enabled.
+// In debug build we will randomly insert in either the front or back of
+// the group.
+// TODO(kfm,sbenza): revisit after we do unconditional mixing
+template <class Mask>
+Y_ABSL_ATTRIBUTE_ALWAYS_INLINE inline auto GetInsertionOffset(
+    Mask mask, Y_ABSL_ATTRIBUTE_UNUSED size_t capacity,
+    Y_ABSL_ATTRIBUTE_UNUSED size_t hash,
+    Y_ABSL_ATTRIBUTE_UNUSED const ctrl_t* ctrl) {
+#if defined(NDEBUG)
+  return mask.LowestBitSet();
+#else
+  return ShouldInsertBackwardsForDebug(capacity, hash, ctrl)
+             ? mask.HighestBitSet()
+             : mask.LowestBitSet();
+#endif
+}
 
 // Returns a per-table, hash salt, which changes on resize. This gets mixed into
 // H1 to randomize iteration order per-table.
@@ -560,7 +623,12 @@ inline h2_t H2(size_t hash) { return hash & 0x7F; }
 
 // Helpers for checking the state of a control byte.
 inline bool IsEmpty(ctrl_t c) { return c == ctrl_t::kEmpty; }
-inline bool IsFull(ctrl_t c) { return c >= static_cast<ctrl_t>(0); }
+inline bool IsFull(ctrl_t c) {
+  // Cast `c` to the underlying type instead of casting `0` to `ctrl_t` as `0`
+  // is not a value in the enum. Both ways are equivalent, but this way makes
+  // linters happier.
+  return static_cast<std::underlying_type_t<ctrl_t>>(c) >= 0;
+}
 inline bool IsDeleted(ctrl_t c) { return c == ctrl_t::kDeleted; }
 inline bool IsEmptyOrDeleted(ctrl_t c) { return c < ctrl_t::kSentinel; }
 
@@ -646,6 +714,14 @@ struct GroupSse2Impl {
         static_cast<uint16_t>(_mm_movemask_epi8(ctrl) ^ 0xffff));
   }
 
+  // Returns a bitmask representing the positions of non full slots.
+  // Note: this includes: kEmpty, kDeleted, kSentinel.
+  // It is useful in contexts when kSentinel is not present.
+  auto MaskNonFull() const {
+    return BitMask<uint16_t, kWidth>(
+        static_cast<uint16_t>(_mm_movemask_epi8(ctrl)));
+  }
+
   // Returns a bitmask representing the positions of empty or deleted slots.
   NonIterableBitMask<uint16_t, kWidth> MaskEmptyOrDeleted() const {
     auto special = _mm_set1_epi8(static_cast<char>(ctrl_t::kSentinel));
@@ -685,10 +761,11 @@ struct GroupAArch64Impl {
     ctrl = vld1_u8(reinterpret_cast<const uint8_t*>(pos));
   }
 
-  BitMask<uint64_t, kWidth, 3> Match(h2_t hash) const {
+  auto Match(h2_t hash) const {
     uint8x8_t dup = vdup_n_u8(hash);
     auto mask = vceq_u8(ctrl, dup);
-    return BitMask<uint64_t, kWidth, 3>(
+    return BitMask<uint64_t, kWidth, /*Shift=*/3,
+                   /*NullifyBitsOnIteration=*/true>(
         vget_lane_u64(vreinterpret_u64_u8(mask), 0));
   }
 
@@ -704,12 +781,25 @@ struct GroupAArch64Impl {
   // Returns a bitmask representing the positions of full slots.
   // Note: for `is_small()` tables group may contain the "same" slot twice:
   // original and mirrored.
-  BitMask<uint64_t, kWidth, 3> MaskFull() const {
+  auto MaskFull() const {
     uint64_t mask = vget_lane_u64(
         vreinterpret_u64_u8(vcge_s8(vreinterpret_s8_u8(ctrl),
                                     vdup_n_s8(static_cast<int8_t>(0)))),
         0);
-    return BitMask<uint64_t, kWidth, 3>(mask);
+    return BitMask<uint64_t, kWidth, /*Shift=*/3,
+                   /*NullifyBitsOnIteration=*/true>(mask);
+  }
+
+  // Returns a bitmask representing the positions of non full slots.
+  // Note: this includes: kEmpty, kDeleted, kSentinel.
+  // It is useful in contexts when kSentinel is not present.
+  auto MaskNonFull() const {
+    uint64_t mask = vget_lane_u64(
+        vreinterpret_u64_u8(vclt_s8(vreinterpret_s8_u8(ctrl),
+                                    vdup_n_s8(static_cast<int8_t>(0)))),
+        0);
+    return BitMask<uint64_t, kWidth, /*Shift=*/3,
+                   /*NullifyBitsOnIteration=*/true>(mask);
   }
 
   NonIterableBitMask<uint64_t, kWidth, 3> MaskEmptyOrDeleted() const {
@@ -736,11 +826,10 @@ struct GroupAArch64Impl {
 
   void ConvertSpecialToEmptyAndFullToDeleted(ctrl_t* dst) const {
     uint64_t mask = vget_lane_u64(vreinterpret_u64_u8(ctrl), 0);
-    constexpr uint64_t msbs = 0x8080808080808080ULL;
     constexpr uint64_t slsbs = 0x0202020202020202ULL;
     constexpr uint64_t midbs = 0x7e7e7e7e7e7e7e7eULL;
     auto x = slsbs & (mask >> 6);
-    auto res = (x + midbs) | msbs;
+    auto res = (x + midbs) | kMsbs8Bytes;
     little_endian::Store64(dst, res);
   }
 
@@ -768,30 +857,33 @@ struct GroupPortableImpl {
     //   v = 0x1716151413121110
     //   hash = 0x12
     //   retval = (v - lsbs) & ~v & msbs = 0x0000000080800000
-    constexpr uint64_t msbs = 0x8080808080808080ULL;
     constexpr uint64_t lsbs = 0x0101010101010101ULL;
     auto x = ctrl ^ (lsbs * hash);
-    return BitMask<uint64_t, kWidth, 3>((x - lsbs) & ~x & msbs);
+    return BitMask<uint64_t, kWidth, 3>((x - lsbs) & ~x & kMsbs8Bytes);
   }
 
   NonIterableBitMask<uint64_t, kWidth, 3> MaskEmpty() const {
-    constexpr uint64_t msbs = 0x8080808080808080ULL;
     return NonIterableBitMask<uint64_t, kWidth, 3>((ctrl & ~(ctrl << 6)) &
-                                                   msbs);
+                                                   kMsbs8Bytes);
   }
 
   // Returns a bitmask representing the positions of full slots.
   // Note: for `is_small()` tables group may contain the "same" slot twice:
   // original and mirrored.
   BitMask<uint64_t, kWidth, 3> MaskFull() const {
-    constexpr uint64_t msbs = 0x8080808080808080ULL;
-    return BitMask<uint64_t, kWidth, 3>((ctrl ^ msbs) & msbs);
+    return BitMask<uint64_t, kWidth, 3>((ctrl ^ kMsbs8Bytes) & kMsbs8Bytes);
+  }
+
+  // Returns a bitmask representing the positions of non full slots.
+  // Note: this includes: kEmpty, kDeleted, kSentinel.
+  // It is useful in contexts when kSentinel is not present.
+  auto MaskNonFull() const {
+    return BitMask<uint64_t, kWidth, 3>(ctrl & kMsbs8Bytes);
   }
 
   NonIterableBitMask<uint64_t, kWidth, 3> MaskEmptyOrDeleted() const {
-    constexpr uint64_t msbs = 0x8080808080808080ULL;
     return NonIterableBitMask<uint64_t, kWidth, 3>((ctrl & ~(ctrl << 7)) &
-                                                   msbs);
+                                                   kMsbs8Bytes);
   }
 
   uint32_t CountLeadingEmptyOrDeleted() const {
@@ -803,9 +895,8 @@ struct GroupPortableImpl {
   }
 
   void ConvertSpecialToEmptyAndFullToDeleted(ctrl_t* dst) const {
-    constexpr uint64_t msbs = 0x8080808080808080ULL;
     constexpr uint64_t lsbs = 0x0101010101010101ULL;
-    auto x = ctrl & msbs;
+    auto x = ctrl & kMsbs8Bytes;
     auto res = (~x + (x >> 7)) & ~lsbs;
     little_endian::Store64(dst, res);
   }
@@ -815,21 +906,21 @@ struct GroupPortableImpl {
 
 #ifdef Y_ABSL_INTERNAL_HAVE_SSE2
 using Group = GroupSse2Impl;
-using GroupEmptyOrDeleted = GroupSse2Impl;
+using GroupFullEmptyOrDeleted = GroupSse2Impl;
 #elif defined(Y_ABSL_INTERNAL_HAVE_ARM_NEON) && defined(Y_ABSL_IS_LITTLE_ENDIAN)
 using Group = GroupAArch64Impl;
 // For Aarch64, we use the portable implementation for counting and masking
-// empty or deleted group elements. This is to avoid the latency of moving
+// full, empty or deleted group elements. This is to avoid the latency of moving
 // between data GPRs and Neon registers when it does not provide a benefit.
 // Using Neon is profitable when we call Match(), but is not when we don't,
-// which is the case when we do *EmptyOrDeleted operations. It is difficult to
-// make a similar approach beneficial on other architectures such as x86 since
-// they have much lower GPR <-> vector register transfer latency and 16-wide
-// Groups.
-using GroupEmptyOrDeleted = GroupPortableImpl;
+// which is the case when we do *EmptyOrDeleted and MaskFull operations.
+// It is difficult to make a similar approach beneficial on other architectures
+// such as x86 since they have much lower GPR <-> vector register transfer
+// latency and 16-wide Groups.
+using GroupFullEmptyOrDeleted = GroupPortableImpl;
 #else
 using Group = GroupPortableImpl;
-using GroupEmptyOrDeleted = GroupPortableImpl;
+using GroupFullEmptyOrDeleted = GroupPortableImpl;
 #endif
 
 // When there is an insertion with no reserved growth, we rehash with
@@ -978,17 +1069,96 @@ using CommonFieldsGenerationInfo = CommonFieldsGenerationInfoDisabled;
 using HashSetIteratorGenerationInfo = HashSetIteratorGenerationInfoDisabled;
 #endif
 
+// Stored the information regarding number of slots we can still fill
+// without needing to rehash.
+//
+// We want to ensure sufficient number of empty slots in the table in order
+// to keep probe sequences relatively short. Empty slot in the probe group
+// is required to stop probing.
+//
+// Tombstones (kDeleted slots) are not included in the growth capacity,
+// because we'd like to rehash when the table is filled with tombstones and/or
+// full slots.
+//
+// GrowthInfo also stores a bit that encodes whether table may have any
+// deleted slots.
+// Most of the tables (>95%) have no deleted slots, so some functions can
+// be more efficient with this information.
+//
+// Callers can also force a rehash via the standard `rehash(0)`,
+// which will recompute this value as a side-effect.
+//
+// See also `CapacityToGrowth()`.
+class GrowthInfo {
+ public:
+  // Leaves data member uninitialized.
+  GrowthInfo() = default;
+
+  // Initializes the GrowthInfo assuming we can grow `growth_left` elements
+  // and there are no kDeleted slots in the table.
+  void InitGrowthLeftNoDeleted(size_t growth_left) {
+    growth_left_info_ = growth_left;
+  }
+
+  // Overwrites single full slot with an empty slot.
+  void OverwriteFullAsEmpty() { ++growth_left_info_; }
+
+  // Overwrites single empty slot with a full slot.
+  void OverwriteEmptyAsFull() {
+    assert(GetGrowthLeft() > 0);
+    --growth_left_info_;
+  }
+
+  // Overwrites several empty slots with full slots.
+  void OverwriteManyEmptyAsFull(size_t cnt) {
+    assert(GetGrowthLeft() >= cnt);
+    growth_left_info_ -= cnt;
+  }
+
+  // Overwrites specified control element with full slot.
+  void OverwriteControlAsFull(ctrl_t ctrl) {
+    assert(GetGrowthLeft() >= static_cast<size_t>(IsEmpty(ctrl)));
+    growth_left_info_ -= static_cast<size_t>(IsEmpty(ctrl));
+  }
+
+  // Overwrites single full slot with a deleted slot.
+  void OverwriteFullAsDeleted() { growth_left_info_ |= kDeletedBit; }
+
+  // Returns true if table satisfies two properties:
+  // 1. Guaranteed to have no kDeleted slots.
+  // 2. There is a place for at least one element to grow.
+  bool HasNoDeletedAndGrowthLeft() const {
+    return static_cast<std::make_signed_t<size_t>>(growth_left_info_) > 0;
+  }
+
+  // Returns true if the table satisfies two properties:
+  // 1. Guaranteed to have no kDeleted slots.
+  // 2. There is no growth left.
+  bool HasNoGrowthLeftAndNoDeleted() const { return growth_left_info_ == 0; }
+
+  // Returns true if table guaranteed to have no k
+  bool HasNoDeleted() const {
+    return static_cast<std::make_signed_t<size_t>>(growth_left_info_) >= 0;
+  }
+
+  // Returns the number of elements left to grow.
+  size_t GetGrowthLeft() const { return growth_left_info_ & kGrowthLeftMask; }
+
+ private:
+  static constexpr size_t kGrowthLeftMask = ((~size_t{}) >> 1);
+  static constexpr size_t kDeletedBit = ~kGrowthLeftMask;
+  // Topmost bit signal whenever there are deleted slots.
+  size_t growth_left_info_;
+};
+
+static_assert(sizeof(GrowthInfo) == sizeof(size_t), "");
+static_assert(alignof(GrowthInfo) == alignof(size_t), "");
+
 // Returns whether `n` is a valid capacity (i.e., number of slots).
 //
 // A valid capacity is a non-zero integer `2^m - 1`.
 inline bool IsValidCapacity(size_t n) { return ((n + 1) & n) == 0 && n > 0; }
 
-// Computes the offset from the start of the backing allocation of control.
-// infoz and growth_left are stored at the beginning of the backing array.
-inline size_t ControlOffset(bool has_infoz) {
-  return (has_infoz ? sizeof(HashtablezInfoHandle) : 0) + sizeof(size_t);
-}
-
 // Returns the number of "cloned control bytes".
 //
 // This is the number of control bytes that are present both at the beginning
@@ -996,36 +1166,157 @@ inline size_t ControlOffset(bool has_infoz) {
 // `Group::kWidth`-width probe window starting from any control byte.
 constexpr size_t NumClonedBytes() { return Group::kWidth - 1; }
 
-// Given the capacity of a table, computes the offset (from the start of the
-// backing allocation) of the generation counter (if it exists).
-inline size_t GenerationOffset(size_t capacity, bool has_infoz) {
-  assert(IsValidCapacity(capacity));
-  const size_t num_control_bytes = capacity + 1 + NumClonedBytes();
-  return ControlOffset(has_infoz) + num_control_bytes;
+// Returns the number of control bytes including cloned.
+constexpr size_t NumControlBytes(size_t capacity) {
+  return capacity + 1 + NumClonedBytes();
 }
 
-// Given the capacity of a table, computes the offset (from the start of the
-// backing allocation) at which the slots begin.
-inline size_t SlotOffset(size_t capacity, size_t slot_align, bool has_infoz) {
-  assert(IsValidCapacity(capacity));
-  return (GenerationOffset(capacity, has_infoz) + NumGenerationBytes() +
-          slot_align - 1) &
-         (~slot_align + 1);
+// Computes the offset from the start of the backing allocation of control.
+// infoz and growth_info are stored at the beginning of the backing array.
+inline static size_t ControlOffset(bool has_infoz) {
+  return (has_infoz ? sizeof(HashtablezInfoHandle) : 0) + sizeof(GrowthInfo);
 }
 
-// Given the capacity of a table, computes the total size of the backing
-// array.
-inline size_t AllocSize(size_t capacity, size_t slot_size, size_t slot_align,
-                        bool has_infoz) {
-  return SlotOffset(capacity, slot_align, has_infoz) + capacity * slot_size;
-}
+// Helper class for computing offsets and allocation size of hash set fields.
+class RawHashSetLayout {
+ public:
+  explicit RawHashSetLayout(size_t capacity, size_t slot_align, bool has_infoz)
+      : capacity_(capacity),
+        control_offset_(ControlOffset(has_infoz)),
+        generation_offset_(control_offset_ + NumControlBytes(capacity)),
+        slot_offset_(
+            (generation_offset_ + NumGenerationBytes() + slot_align - 1) &
+            (~slot_align + 1)) {
+    assert(IsValidCapacity(capacity));
+  }
+
+  // Returns the capacity of a table.
+  size_t capacity() const { return capacity_; }
+
+  // Returns precomputed offset from the start of the backing allocation of
+  // control.
+  size_t control_offset() const { return control_offset_; }
+
+  // Given the capacity of a table, computes the offset (from the start of the
+  // backing allocation) of the generation counter (if it exists).
+  size_t generation_offset() const { return generation_offset_; }
+
+  // Given the capacity of a table, computes the offset (from the start of the
+  // backing allocation) at which the slots begin.
+  size_t slot_offset() const { return slot_offset_; }
+
+  // Given the capacity of a table, computes the total size of the backing
+  // array.
+  size_t alloc_size(size_t slot_size) const {
+    return slot_offset_ + capacity_ * slot_size;
+  }
+
+ private:
+  size_t capacity_;
+  size_t control_offset_;
+  size_t generation_offset_;
+  size_t slot_offset_;
+};
+
+struct HashtableFreeFunctionsAccess;
+
+// We only allow a maximum of 1 SOO element, which makes the implementation
+// much simpler. Complications with multiple SOO elements include:
+// - Satisfying the guarantee that erasing one element doesn't invalidate
+//   iterators to other elements means we would probably need actual SOO
+//   control bytes.
+// - In order to prevent user code from depending on iteration order for small
+//   tables, we would need to randomize the iteration order somehow.
+constexpr size_t SooCapacity() { return 1; }
+// Sentinel type to indicate SOO CommonFields construction.
+struct soo_tag_t {};
+// Sentinel type to indicate SOO CommonFields construction with full size.
+struct full_soo_tag_t {};
+
+// Suppress erroneous uninitialized memory errors on GCC. For example, GCC
+// thinks that the call to slot_array() in find_or_prepare_insert() is reading
+// uninitialized memory, but slot_array is only called there when the table is
+// non-empty and this memory is initialized when the table is non-empty.
+#if !defined(__clang__) && defined(__GNUC__)
+#define Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED(x)                    \
+  _Pragma("GCC diagnostic push")                                   \
+      _Pragma("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")  \
+          _Pragma("GCC diagnostic ignored \"-Wuninitialized\"") x; \
+  _Pragma("GCC diagnostic pop")
+#define Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(x) \
+  Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED(return x)
+#else
+#define Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED(x) x
+#define Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(x) return x
+#endif
+
+// This allows us to work around an uninitialized memory warning when
+// constructing begin() iterators in empty hashtables.
+union MaybeInitializedPtr {
+  void* get() const { Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(p); }
+  void set(void* ptr) { p = ptr; }
+
+  void* p;
+};
+
+struct HeapPtrs {
+  HeapPtrs() = default;
+  explicit HeapPtrs(ctrl_t* c) : control(c) {}
+
+  // The control bytes (and, also, a pointer near to the base of the backing
+  // array).
+  //
+  // This contains `capacity + 1 + NumClonedBytes()` entries, even
+  // when the table is empty (hence EmptyGroup).
+  //
+  // Note that growth_info is stored immediately before this pointer.
+  // May be uninitialized for SOO tables.
+  ctrl_t* control;
+
+  // The beginning of the slots, located at `SlotOffset()` bytes after
+  // `control`. May be uninitialized for empty tables.
+  // Note: we can't use `slots` because Qt defines "slots" as a macro.
+  MaybeInitializedPtr slot_array;
+};
+
+// Manages the backing array pointers or the SOO slot. When raw_hash_set::is_soo
+// is true, the SOO slot is stored in `soo_data`. Otherwise, we use `heap`.
+union HeapOrSoo {
+  HeapOrSoo() = default;
+  explicit HeapOrSoo(ctrl_t* c) : heap(c) {}
+
+  ctrl_t*& control() {
+    Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(heap.control);
+  }
+  ctrl_t* control() const {
+    Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(heap.control);
+  }
+  MaybeInitializedPtr& slot_array() {
+    Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(heap.slot_array);
+  }
+  MaybeInitializedPtr slot_array() const {
+    Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(heap.slot_array);
+  }
+  void* get_soo_data() {
+    Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(soo_data);
+  }
+  const void* get_soo_data() const {
+    Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN(soo_data);
+  }
+
+  HeapPtrs heap;
+  unsigned char soo_data[sizeof(HeapPtrs)];
+};
 
 // CommonFields hold the fields in raw_hash_set that do not depend
 // on template parameters. This allows us to conveniently pass all
 // of this state to helper functions as a single argument.
 class CommonFields : public CommonFieldsGenerationInfo {
  public:
-  CommonFields() = default;
+  CommonFields() : capacity_(0), size_(0), heap_or_soo_(EmptyGroup()) {}
+  explicit CommonFields(soo_tag_t) : capacity_(SooCapacity()), size_(0) {}
+  explicit CommonFields(full_soo_tag_t)
+      : capacity_(SooCapacity()), size_(size_t{1} << HasInfozShift()) {}
 
   // Not copyable
   CommonFields(const CommonFields&) = delete;
@@ -1035,23 +1326,44 @@ class CommonFields : public CommonFieldsGenerationInfo {
   CommonFields(CommonFields&& that) = default;
   CommonFields& operator=(CommonFields&&) = default;
 
-  ctrl_t* control() const { return control_; }
-  void set_control(ctrl_t* c) { control_ = c; }
+  template <bool kSooEnabled>
+  static CommonFields CreateDefault() {
+    return kSooEnabled ? CommonFields{soo_tag_t{}} : CommonFields{};
+  }
+
+  // The inline data for SOO is written on top of control_/slots_.
+  const void* soo_data() const { return heap_or_soo_.get_soo_data(); }
+  void* soo_data() { return heap_or_soo_.get_soo_data(); }
+
+  HeapOrSoo heap_or_soo() const { return heap_or_soo_; }
+  const HeapOrSoo& heap_or_soo_ref() const { return heap_or_soo_; }
+
+  ctrl_t* control() const { return heap_or_soo_.control(); }
+  void set_control(ctrl_t* c) { heap_or_soo_.control() = c; }
   void* backing_array_start() const {
-    // growth_left (and maybe infoz) is stored before control bytes.
+    // growth_info (and maybe infoz) is stored before control bytes.
     assert(reinterpret_cast<uintptr_t>(control()) % alignof(size_t) == 0);
     return control() - ControlOffset(has_infoz());
   }
 
   // Note: we can't use slots() because Qt defines "slots" as a macro.
-  void* slot_array() const { return slots_; }
-  void set_slots(void* s) { slots_ = s; }
+  void* slot_array() const { return heap_or_soo_.slot_array().get(); }
+  MaybeInitializedPtr slots_union() const { return heap_or_soo_.slot_array(); }
+  void set_slots(void* s) { heap_or_soo_.slot_array().set(s); }
 
   // The number of filled slots.
   size_t size() const { return size_ >> HasInfozShift(); }
   void set_size(size_t s) {
     size_ = (s << HasInfozShift()) | (size_ & HasInfozMask());
   }
+  void set_empty_soo() {
+    AssertInSooMode();
+    size_ = 0;
+  }
+  void set_full_soo() {
+    AssertInSooMode();
+    size_ = size_t{1} << HasInfozShift();
+  }
   void increment_size() {
     assert(size() < capacity());
     size_ += size_t{1} << HasInfozShift();
@@ -1070,15 +1382,17 @@ class CommonFields : public CommonFieldsGenerationInfo {
 
   // The number of slots we can still fill without needing to rehash.
   // This is stored in the heap allocation before the control bytes.
-  size_t growth_left() const {
-    const size_t* gl_ptr = reinterpret_cast<size_t*>(control()) - 1;
-    assert(reinterpret_cast<uintptr_t>(gl_ptr) % alignof(size_t) == 0);
+  // TODO(b/289225379): experiment with moving growth_info back inline to
+  // increase room for SOO.
+  size_t growth_left() const { return growth_info().GetGrowthLeft(); }
+
+  GrowthInfo& growth_info() {
+    auto* gl_ptr = reinterpret_cast<GrowthInfo*>(control()) - 1;
+    assert(reinterpret_cast<uintptr_t>(gl_ptr) % alignof(GrowthInfo) == 0);
     return *gl_ptr;
   }
-  void set_growth_left(size_t gl) {
-    size_t* gl_ptr = reinterpret_cast<size_t*>(control()) - 1;
-    assert(reinterpret_cast<uintptr_t>(gl_ptr) % alignof(size_t) == 0);
-    *gl_ptr = gl;
+  GrowthInfo growth_info() const {
+    return const_cast<CommonFields*>(this)->growth_info();
   }
 
   bool has_infoz() const {
@@ -1103,12 +1417,8 @@ class CommonFields : public CommonFieldsGenerationInfo {
         should_rehash_for_bug_detection_on_insert(control(), capacity());
   }
   bool should_rehash_for_bug_detection_on_move() const {
-    return CommonFieldsGenerationInfo::
-        should_rehash_for_bug_detection_on_move(control(), capacity());
-  }
-  void maybe_increment_generation_on_move() {
-    if (capacity() == 0) return;
-    increment_generation();
+    return CommonFieldsGenerationInfo::should_rehash_for_bug_detection_on_move(
+        control(), capacity());
   }
   void reset_reserved_growth(size_t reservation) {
     CommonFieldsGenerationInfo::reset_reserved_growth(reservation, size());
@@ -1116,7 +1426,16 @@ class CommonFields : public CommonFieldsGenerationInfo {
 
   // The size of the backing array allocation.
   size_t alloc_size(size_t slot_size, size_t slot_align) const {
-    return AllocSize(capacity(), slot_size, slot_align, has_infoz());
+    return RawHashSetLayout(capacity(), slot_align, has_infoz())
+        .alloc_size(slot_size);
+  }
+
+  // Move fields other than heap_or_soo_.
+  void move_non_heap_or_soo_fields(CommonFields& that) {
+    static_cast<CommonFieldsGenerationInfo&>(*this) =
+        std::move(static_cast<CommonFieldsGenerationInfo&>(that));
+    capacity_ = that.capacity_;
+    size_ = that.size_;
   }
 
   // Returns the number of control bytes set to kDeleted. For testing only.
@@ -1132,21 +1451,12 @@ class CommonFields : public CommonFieldsGenerationInfo {
     return (size_t{1} << HasInfozShift()) - 1;
   }
 
-  // TODO(b/182800944): Investigate removing some of these fields:
-  // - control/slots can be derived from each other
-
-  // The control bytes (and, also, a pointer near to the base of the backing
-  // array).
-  //
-  // This contains `capacity + 1 + NumClonedBytes()` entries, even
-  // when the table is empty (hence EmptyGroup).
-  //
-  // Note that growth_left is stored immediately before this pointer.
-  ctrl_t* control_ = EmptyGroup();
-
-  // The beginning of the slots, located at `SlotOffset()` bytes after
-  // `control`. May be null for empty tables.
-  void* slots_ = nullptr;
+  // We can't assert that SOO is enabled because we don't have SooEnabled(), but
+  // we assert what we can.
+  void AssertInSooMode() const {
+    assert(capacity() == SooCapacity());
+    assert(!has_infoz());
+  }
 
   // The number of slots in the backing array. This is always 2^N-1 for an
   // integer N. NOTE: we tried experimenting with compressing the capacity and
@@ -1154,10 +1464,16 @@ class CommonFields : public CommonFieldsGenerationInfo {
   // power (N in 2^N-1), and (b) storing 2^N as the most significant bit of
   // size_ and storing size in the low bits. Both of these experiments were
   // regressions, presumably because we need capacity to do find operations.
-  size_t capacity_ = 0;
+  size_t capacity_;
 
   // The size and also has one bit that stores whether we have infoz.
-  size_t size_ = 0;
+  // TODO(b/289225379): we could put size_ into HeapOrSoo and make capacity_
+  // encode the size in SOO case. We would be making size()/capacity() more
+  // expensive in order to have more SOO space.
+  size_t size_;
+
+  // Either the control/slots pointers or the SOO slot.
+  HeapOrSoo heap_or_soo_;
 };
 
 template <class Policy, class Hash, class Eq, class Alloc>
@@ -1320,6 +1636,10 @@ inline bool AreItersFromSameContainer(const ctrl_t* ctrl_a,
                                       const void* const& slot_b) {
   // If either control byte is null, then we can't tell.
   if (ctrl_a == nullptr || ctrl_b == nullptr) return true;
+  const bool a_is_soo = IsSooControl(ctrl_a);
+  if (a_is_soo != IsSooControl(ctrl_b)) return false;
+  if (a_is_soo) return slot_a == slot_b;
+
   const void* low_slot = slot_a;
   const void* hi_slot = slot_b;
   if (ctrl_a > ctrl_b) {
@@ -1343,41 +1663,45 @@ inline void AssertSameContainer(const ctrl_t* ctrl_a, const ctrl_t* ctrl_b,
   // - use `Y_ABSL_PREDICT_FALSE()` to provide a compiler hint for code layout
   // - use `Y_ABSL_RAW_LOG()` with a format string to reduce code size and improve
   //   the chances that the hot paths will be inlined.
+
+  // fail_if(is_invalid, message) crashes when is_invalid is true and provides
+  // an error message based on `message`.
+  const auto fail_if = [](bool is_invalid, const char* message) {
+    if (Y_ABSL_PREDICT_FALSE(is_invalid)) {
+      Y_ABSL_RAW_LOG(FATAL, "Invalid iterator comparison. %s", message);
+    }
+  };
+
   const bool a_is_default = ctrl_a == EmptyGroup();
   const bool b_is_default = ctrl_b == EmptyGroup();
-  if (Y_ABSL_PREDICT_FALSE(a_is_default != b_is_default)) {
-    Y_ABSL_RAW_LOG(
-        FATAL,
-        "Invalid iterator comparison. Comparing default-constructed iterator "
-        "with non-default-constructed iterator.");
-  }
   if (a_is_default && b_is_default) return;
+  fail_if(a_is_default != b_is_default,
+          "Comparing default-constructed hashtable iterator with a "
+          "non-default-constructed hashtable iterator.");
 
   if (SwisstableGenerationsEnabled()) {
     if (Y_ABSL_PREDICT_TRUE(generation_ptr_a == generation_ptr_b)) return;
+    // Users don't need to know whether the tables are SOO so don't mention SOO
+    // in the debug message.
+    const bool a_is_soo = IsSooControl(ctrl_a);
+    const bool b_is_soo = IsSooControl(ctrl_b);
+    fail_if(a_is_soo != b_is_soo || (a_is_soo && b_is_soo),
+            "Comparing iterators from different hashtables.");
+
     const bool a_is_empty = IsEmptyGeneration(generation_ptr_a);
     const bool b_is_empty = IsEmptyGeneration(generation_ptr_b);
-    if (a_is_empty != b_is_empty) {
-      Y_ABSL_RAW_LOG(FATAL,
-                   "Invalid iterator comparison. Comparing iterator from a "
-                   "non-empty hashtable with an iterator from an empty "
-                   "hashtable.");
-    }
-    if (a_is_empty && b_is_empty) {
-      Y_ABSL_RAW_LOG(FATAL,
-                   "Invalid iterator comparison. Comparing iterators from "
-                   "different empty hashtables.");
-    }
+    fail_if(a_is_empty != b_is_empty,
+            "Comparing an iterator from an empty hashtable with an iterator "
+            "from a non-empty hashtable.");
+    fail_if(a_is_empty && b_is_empty,
+            "Comparing iterators from different empty hashtables.");
+
     const bool a_is_end = ctrl_a == nullptr;
     const bool b_is_end = ctrl_b == nullptr;
-    if (a_is_end || b_is_end) {
-      Y_ABSL_RAW_LOG(FATAL,
-                   "Invalid iterator comparison. Comparing iterator with an "
-                   "end() iterator from a different hashtable.");
-    }
-    Y_ABSL_RAW_LOG(FATAL,
-                 "Invalid iterator comparison. Comparing non-end() iterators "
-                 "from different hashtables.");
+    fail_if(a_is_end || b_is_end,
+            "Comparing iterator with an end() iterator from a different "
+            "hashtable.");
+    fail_if(true, "Comparing non-end() iterators from different hashtables.");
   } else {
     Y_ABSL_HARDENING_ASSERT(
         AreItersFromSameContainer(ctrl_a, ctrl_b, slot_a, slot_b) &&
@@ -1432,20 +1756,17 @@ template <typename = void>
 inline FindInfo find_first_non_full(const CommonFields& common, size_t hash) {
   auto seq = probe(common, hash);
   const ctrl_t* ctrl = common.control();
+  if (IsEmptyOrDeleted(ctrl[seq.offset()]) &&
+      !ShouldInsertBackwards(common.capacity(), hash, ctrl)) {
+    return {seq.offset(), /*probe_length=*/0};
+  }
   while (true) {
-    GroupEmptyOrDeleted g{ctrl + seq.offset()};
+    GroupFullEmptyOrDeleted g{ctrl + seq.offset()};
     auto mask = g.MaskEmptyOrDeleted();
     if (mask) {
-#if !defined(NDEBUG)
-      // We want to add entropy even when ASLR is not enabled.
-      // In debug build we will randomly insert in either the front or back of
-      // the group.
-      // TODO(kfm,sbenza): revisit after we do unconditional mixing
-      if (!is_small(common.capacity()) && ShouldInsertBackwards(hash, ctrl)) {
-        return {seq.offset(mask.HighestBitSet()), seq.index()};
-      }
-#endif
-      return {seq.offset(mask.LowestBitSet()), seq.index()};
+      return {
+          seq.offset(GetInsertionOffset(mask, common.capacity(), hash, ctrl)),
+          seq.index()};
     }
     seq.next();
     assert(seq.index() <= common.capacity() && "full table!");
@@ -1462,7 +1783,8 @@ extern template FindInfo find_first_non_full(const CommonFields&, size_t);
 FindInfo find_first_non_full_outofline(const CommonFields&, size_t);
 
 inline void ResetGrowthLeft(CommonFields& common) {
-  common.set_growth_left(CapacityToGrowth(common.capacity()) - common.size());
+  common.growth_info().InitGrowthLeftNoDeleted(
+      CapacityToGrowth(common.capacity()) - common.size());
 }
 
 // Sets `ctrl` to `{kEmpty, kSentinel, ..., kEmpty}`, marking the entire
@@ -1476,43 +1798,140 @@ inline void ResetCtrl(CommonFields& common, size_t slot_size) {
   SanitizerPoisonMemoryRegion(common.slot_array(), slot_size * capacity);
 }
 
-// Sets `ctrl[i]` to `h`.
-//
-// Unlike setting it directly, this function will perform bounds checks and
-// mirror the value to the cloned tail if necessary.
-inline void SetCtrl(const CommonFields& common, size_t i, ctrl_t h,
-                    size_t slot_size) {
-  const size_t capacity = common.capacity();
-  assert(i < capacity);
-
-  auto* slot_i = static_cast<const char*>(common.slot_array()) + i * slot_size;
+// Sets sanitizer poisoning for slot corresponding to control byte being set.
+inline void DoSanitizeOnSetCtrl(const CommonFields& c, size_t i, ctrl_t h,
+                                size_t slot_size) {
+  assert(i < c.capacity());
+  auto* slot_i = static_cast<const char*>(c.slot_array()) + i * slot_size;
   if (IsFull(h)) {
     SanitizerUnpoisonMemoryRegion(slot_i, slot_size);
   } else {
     SanitizerPoisonMemoryRegion(slot_i, slot_size);
   }
+}
 
-  ctrl_t* ctrl = common.control();
+// Sets `ctrl[i]` to `h`.
+//
+// Unlike setting it directly, this function will perform bounds checks and
+// mirror the value to the cloned tail if necessary.
+inline void SetCtrl(const CommonFields& c, size_t i, ctrl_t h,
+                    size_t slot_size) {
+  DoSanitizeOnSetCtrl(c, i, h, slot_size);
+  ctrl_t* ctrl = c.control();
   ctrl[i] = h;
-  ctrl[((i - NumClonedBytes()) & capacity) + (NumClonedBytes() & capacity)] = h;
+  ctrl[((i - NumClonedBytes()) & c.capacity()) +
+       (NumClonedBytes() & c.capacity())] = h;
+}
+// Overload for setting to an occupied `h2_t` rather than a special `ctrl_t`.
+inline void SetCtrl(const CommonFields& c, size_t i, h2_t h, size_t slot_size) {
+  SetCtrl(c, i, static_cast<ctrl_t>(h), slot_size);
 }
 
+// Like SetCtrl, but in a single group table, we can save some operations when
+// setting the cloned control byte.
+inline void SetCtrlInSingleGroupTable(const CommonFields& c, size_t i, ctrl_t h,
+                                      size_t slot_size) {
+  assert(is_single_group(c.capacity()));
+  DoSanitizeOnSetCtrl(c, i, h, slot_size);
+  ctrl_t* ctrl = c.control();
+  ctrl[i] = h;
+  ctrl[i + c.capacity() + 1] = h;
+}
 // Overload for setting to an occupied `h2_t` rather than a special `ctrl_t`.
-inline void SetCtrl(const CommonFields& common, size_t i, h2_t h,
-                    size_t slot_size) {
-  SetCtrl(common, i, static_cast<ctrl_t>(h), slot_size);
+inline void SetCtrlInSingleGroupTable(const CommonFields& c, size_t i, h2_t h,
+                                      size_t slot_size) {
+  SetCtrlInSingleGroupTable(c, i, static_cast<ctrl_t>(h), slot_size);
 }
 
-// growth_left (which is a size_t) is stored with the backing array.
+// growth_info (which is a size_t) is stored with the backing array.
 constexpr size_t BackingArrayAlignment(size_t align_of_slot) {
-  return (std::max)(align_of_slot, alignof(size_t));
+  return (std::max)(align_of_slot, alignof(GrowthInfo));
 }
 
 // Returns the address of the ith slot in slots where each slot occupies
 // slot_size.
 inline void* SlotAddress(void* slot_array, size_t slot, size_t slot_size) {
-  return reinterpret_cast<void*>(reinterpret_cast<char*>(slot_array) +
-                                 (slot * slot_size));
+  return static_cast<void*>(static_cast<char*>(slot_array) +
+                            (slot * slot_size));
+}
+
+// Iterates over all full slots and calls `cb(const ctrl_t*, SlotType*)`.
+// No insertion to the table allowed during Callback call.
+// Erasure is allowed only for the element passed to the callback.
+template <class SlotType, class Callback>
+Y_ABSL_ATTRIBUTE_ALWAYS_INLINE inline void IterateOverFullSlots(
+    const CommonFields& c, SlotType* slot, Callback cb) {
+  const size_t cap = c.capacity();
+  const ctrl_t* ctrl = c.control();
+  if (is_small(cap)) {
+    // Mirrored/cloned control bytes in small table are also located in the
+    // first group (starting from position 0). We are taking group from position
+    // `capacity` in order to avoid duplicates.
+
+    // Small tables capacity fits into portable group, where
+    // GroupPortableImpl::MaskFull is more efficient for the
+    // capacity <= GroupPortableImpl::kWidth.
+    assert(cap <= GroupPortableImpl::kWidth &&
+           "unexpectedly large small capacity");
+    static_assert(Group::kWidth >= GroupPortableImpl::kWidth,
+                  "unexpected group width");
+    // Group starts from kSentinel slot, so indices in the mask will
+    // be increased by 1.
+    const auto mask = GroupPortableImpl(ctrl + cap).MaskFull();
+    --ctrl;
+    --slot;
+    for (uint32_t i : mask) {
+      cb(ctrl + i, slot + i);
+    }
+    return;
+  }
+  size_t remaining = c.size();
+  Y_ABSL_ATTRIBUTE_UNUSED const size_t original_size_for_assert = remaining;
+  while (remaining != 0) {
+    for (uint32_t i : GroupFullEmptyOrDeleted(ctrl).MaskFull()) {
+      assert(IsFull(ctrl[i]) && "hash table was modified unexpectedly");
+      cb(ctrl + i, slot + i);
+      --remaining;
+    }
+    ctrl += Group::kWidth;
+    slot += Group::kWidth;
+    assert((remaining == 0 || *(ctrl - 1) != ctrl_t::kSentinel) &&
+           "hash table was modified unexpectedly");
+  }
+  // NOTE: erasure of the current element is allowed in callback for
+  // y_absl::erase_if specialization. So we use `>=`.
+  assert(original_size_for_assert >= c.size() &&
+         "hash table was modified unexpectedly");
+}
+
+template <typename CharAlloc>
+constexpr bool ShouldSampleHashtablezInfo() {
+  // Folks with custom allocators often make unwarranted assumptions about the
+  // behavior of their classes vis-a-vis trivial destructability and what
+  // calls they will or won't make.  Avoid sampling for people with custom
+  // allocators to get us out of this mess.  This is not a hard guarantee but
+  // a workaround while we plan the exact guarantee we want to provide.
+  return std::is_same<CharAlloc, std::allocator<char>>::value;
+}
+
+template <bool kSooEnabled>
+HashtablezInfoHandle SampleHashtablezInfo(size_t sizeof_slot, size_t sizeof_key,
+                                          size_t sizeof_value,
+                                          size_t old_capacity, bool was_soo,
+                                          HashtablezInfoHandle forced_infoz,
+                                          CommonFields& c) {
+  if (forced_infoz.IsSampled()) return forced_infoz;
+  // In SOO, we sample on the first insertion so if this is an empty SOO case
+  // (e.g. when reserve is called), then we still need to sample.
+  if (kSooEnabled && was_soo && c.size() == 0) {
+    return Sample(sizeof_slot, sizeof_key, sizeof_value, SooCapacity());
+  }
+  // For non-SOO cases, we sample whenever the capacity is increasing from zero
+  // to non-zero.
+  if (!kSooEnabled && old_capacity == 0) {
+    return Sample(sizeof_slot, sizeof_key, sizeof_value, 0);
+  }
+  return c.infoz();
 }
 
 // Helper class to perform resize of the hash set.
@@ -1521,17 +1940,21 @@ inline void* SlotAddress(void* slot_array, size_t slot, size_t slot_size) {
 // See GrowIntoSingleGroupShuffleControlBytes for details.
 class HashSetResizeHelper {
  public:
-  explicit HashSetResizeHelper(CommonFields& c)
-      : old_ctrl_(c.control()),
-        old_capacity_(c.capacity()),
-        had_infoz_(c.has_infoz()) {}
-
-  // Optimized for small groups version of `find_first_non_full` applicable
-  // only right after calling `raw_hash_set::resize`.
+  explicit HashSetResizeHelper(CommonFields& c, bool was_soo, bool had_soo_slot,
+                               HashtablezInfoHandle forced_infoz)
+      : old_capacity_(c.capacity()),
+        had_infoz_(c.has_infoz()),
+        was_soo_(was_soo),
+        had_soo_slot_(had_soo_slot),
+        forced_infoz_(forced_infoz) {}
+
+  // Optimized for small groups version of `find_first_non_full`.
+  // Beneficial only right after calling `raw_hash_set::resize`.
+  // It is safe to call in case capacity is big or was not changed, but there
+  // will be no performance benefit.
   // It has implicit assumption that `resize` will call
   // `GrowSizeIntoSingleGroup*` in case `IsGrowingIntoSingleGroupApplicable`.
-  // Falls back to `find_first_non_full` in case of big groups, so it is
-  // safe to use after `rehash_and_grow_if_necessary`.
+  // Falls back to `find_first_non_full` in case of big groups.
   static FindInfo FindFirstNonFullAfterResize(const CommonFields& c,
                                               size_t old_capacity,
                                               size_t hash) {
@@ -1553,14 +1976,30 @@ class HashSetResizeHelper {
     return FindInfo{offset, 0};
   }
 
-  ctrl_t* old_ctrl() const { return old_ctrl_; }
+  HeapOrSoo& old_heap_or_soo() { return old_heap_or_soo_; }
+  void* old_soo_data() { return old_heap_or_soo_.get_soo_data(); }
+  ctrl_t* old_ctrl() const {
+    assert(!was_soo_);
+    return old_heap_or_soo_.control();
+  }
+  void* old_slots() const {
+    assert(!was_soo_);
+    return old_heap_or_soo_.slot_array().get();
+  }
   size_t old_capacity() const { return old_capacity_; }
 
+  // Returns the index of the SOO slot when growing from SOO to non-SOO in a
+  // single group. See also InitControlBytesAfterSoo(). It's important to use
+  // index 1 so that when resizing from capacity 1 to 3, we can still have
+  // random iteration order between the first two inserted elements.
+  // I.e. it allows inserting the second element at either index 0 or 2.
+  static size_t SooSlotIndex() { return 1; }
+
   // Allocates a backing array for the hashtable.
   // Reads `capacity` and updates all other fields based on the result of
   // the allocation.
   //
-  // It also may do the folowing actions:
+  // It also may do the following actions:
   // 1. initialize control bytes
   // 2. initialize slots
   // 3. deallocate old slots.
@@ -1590,45 +2029,45 @@ class HashSetResizeHelper {
   //
   //  Returns IsGrowingIntoSingleGroupApplicable result to avoid recomputation.
   template <typename Alloc, size_t SizeOfSlot, bool TransferUsesMemcpy,
-            size_t AlignOfSlot>
-  Y_ABSL_ATTRIBUTE_NOINLINE bool InitializeSlots(CommonFields& c, void* old_slots,
-                                               Alloc alloc) {
+            bool SooEnabled, size_t AlignOfSlot>
+  Y_ABSL_ATTRIBUTE_NOINLINE bool InitializeSlots(CommonFields& c, Alloc alloc,
+                                               ctrl_t soo_slot_h2,
+                                               size_t key_size,
+                                               size_t value_size) {
     assert(c.capacity());
-    // Folks with custom allocators often make unwarranted assumptions about the
-    // behavior of their classes vis-a-vis trivial destructability and what
-    // calls they will or won't make.  Avoid sampling for people with custom
-    // allocators to get us out of this mess.  This is not a hard guarantee but
-    // a workaround while we plan the exact guarantee we want to provide.
-    const size_t sample_size =
-        (std::is_same<Alloc, std::allocator<char>>::value &&
-         c.slot_array() == nullptr)
-            ? SizeOfSlot
-            : 0;
     HashtablezInfoHandle infoz =
-        sample_size > 0 ? Sample(sample_size) : c.infoz();
+        ShouldSampleHashtablezInfo<Alloc>()
+            ? SampleHashtablezInfo<SooEnabled>(SizeOfSlot, key_size, value_size,
+                                               old_capacity_, was_soo_,
+                                               forced_infoz_, c)
+            : HashtablezInfoHandle{};
 
     const bool has_infoz = infoz.IsSampled();
-    const size_t cap = c.capacity();
-    const size_t alloc_size =
-        AllocSize(cap, SizeOfSlot, AlignOfSlot, has_infoz);
-    char* mem = static_cast<char*>(
-        Allocate<BackingArrayAlignment(AlignOfSlot)>(&alloc, alloc_size));
+    RawHashSetLayout layout(c.capacity(), AlignOfSlot, has_infoz);
+    char* mem = static_cast<char*>(Allocate<BackingArrayAlignment(AlignOfSlot)>(
+        &alloc, layout.alloc_size(SizeOfSlot)));
     const GenerationType old_generation = c.generation();
-    c.set_generation_ptr(reinterpret_cast<GenerationType*>(
-        mem + GenerationOffset(cap, has_infoz)));
+    c.set_generation_ptr(
+        reinterpret_cast<GenerationType*>(mem + layout.generation_offset()));
     c.set_generation(NextGeneration(old_generation));
-    c.set_control(reinterpret_cast<ctrl_t*>(mem + ControlOffset(has_infoz)));
-    c.set_slots(mem + SlotOffset(cap, AlignOfSlot, has_infoz));
+    c.set_control(reinterpret_cast<ctrl_t*>(mem + layout.control_offset()));
+    c.set_slots(mem + layout.slot_offset());
     ResetGrowthLeft(c);
 
     const bool grow_single_group =
-        IsGrowingIntoSingleGroupApplicable(old_capacity_, c.capacity());
-    if (old_capacity_ != 0 && grow_single_group) {
+        IsGrowingIntoSingleGroupApplicable(old_capacity_, layout.capacity());
+    if (SooEnabled && was_soo_ && grow_single_group) {
+      InitControlBytesAfterSoo(c.control(), soo_slot_h2, layout.capacity());
+      if (TransferUsesMemcpy && had_soo_slot_) {
+        TransferSlotAfterSoo(c, SizeOfSlot);
+      }
+      // SooEnabled implies that old_capacity_ != 0.
+    } else if ((SooEnabled || old_capacity_ != 0) && grow_single_group) {
       if (TransferUsesMemcpy) {
-        GrowSizeIntoSingleGroupTransferable(c, old_slots, SizeOfSlot);
-        DeallocateOld<AlignOfSlot>(alloc, SizeOfSlot, old_slots);
+        GrowSizeIntoSingleGroupTransferable(c, SizeOfSlot);
+        DeallocateOld<AlignOfSlot>(alloc, SizeOfSlot);
       } else {
-        GrowIntoSingleGroupShuffleControlBytes(c.control(), c.capacity());
+        GrowIntoSingleGroupShuffleControlBytes(c.control(), layout.capacity());
       }
     } else {
       ResetCtrl(c, SizeOfSlot);
@@ -1636,8 +2075,8 @@ class HashSetResizeHelper {
 
     c.set_has_infoz(has_infoz);
     if (has_infoz) {
-      infoz.RecordStorageChanged(c.size(), cap);
-      if (grow_single_group || old_capacity_ == 0) {
+      infoz.RecordStorageChanged(c.size(), layout.capacity());
+      if ((SooEnabled && was_soo_) || grow_single_group || old_capacity_ == 0) {
         infoz.RecordRehash(0);
       }
       c.set_infoz(infoz);
@@ -1651,21 +2090,22 @@ class HashSetResizeHelper {
   // PRECONDITIONS:
   // 1. GrowIntoSingleGroupShuffleControlBytes was already called.
   template <class PolicyTraits, class Alloc>
-  void GrowSizeIntoSingleGroup(CommonFields& c, Alloc& alloc_ref,
-                               typename PolicyTraits::slot_type* old_slots) {
+  void GrowSizeIntoSingleGroup(CommonFields& c, Alloc& alloc_ref) {
     assert(old_capacity_ < Group::kWidth / 2);
     assert(IsGrowingIntoSingleGroupApplicable(old_capacity_, c.capacity()));
     using slot_type = typename PolicyTraits::slot_type;
     assert(is_single_group(c.capacity()));
 
-    auto* new_slots = reinterpret_cast<slot_type*>(c.slot_array());
+    auto* new_slots = static_cast<slot_type*>(c.slot_array());
+    auto* old_slots_ptr = static_cast<slot_type*>(old_slots());
 
     size_t shuffle_bit = old_capacity_ / 2 + 1;
     for (size_t i = 0; i < old_capacity_; ++i) {
-      if (IsFull(old_ctrl_[i])) {
+      if (IsFull(old_ctrl()[i])) {
         size_t new_i = i ^ shuffle_bit;
         SanitizerUnpoisonMemoryRegion(new_slots + new_i, sizeof(slot_type));
-        PolicyTraits::transfer(&alloc_ref, new_slots + new_i, old_slots + i);
+        PolicyTraits::transfer(&alloc_ref, new_slots + new_i,
+                               old_slots_ptr + i);
       }
     }
     PoisonSingleGroupEmptySlots(c, sizeof(slot_type));
@@ -1673,11 +2113,12 @@ class HashSetResizeHelper {
 
   // Deallocates old backing array.
   template <size_t AlignOfSlot, class CharAlloc>
-  void DeallocateOld(CharAlloc alloc_ref, size_t slot_size, void* old_slots) {
-    SanitizerUnpoisonMemoryRegion(old_slots, slot_size * old_capacity_);
+  void DeallocateOld(CharAlloc alloc_ref, size_t slot_size) {
+    SanitizerUnpoisonMemoryRegion(old_slots(), slot_size * old_capacity_);
+    auto layout = RawHashSetLayout(old_capacity_, AlignOfSlot, had_infoz_);
     Deallocate<BackingArrayAlignment(AlignOfSlot)>(
-        &alloc_ref, old_ctrl_ - ControlOffset(had_infoz_),
-        AllocSize(old_capacity_, slot_size, AlignOfSlot, had_infoz_));
+        &alloc_ref, old_ctrl() - layout.control_offset(),
+        layout.alloc_size(slot_size));
   }
 
  private:
@@ -1692,8 +2133,12 @@ class HashSetResizeHelper {
   // Relocates control bytes and slots into new single group for
   // transferable objects.
   // Must be called only if IsGrowingIntoSingleGroupApplicable returned true.
-  void GrowSizeIntoSingleGroupTransferable(CommonFields& c, void* old_slots,
-                                           size_t slot_size);
+  void GrowSizeIntoSingleGroupTransferable(CommonFields& c, size_t slot_size);
+
+  // If there was an SOO slot and slots are transferable, transfers the SOO slot
+  // into the new heap allocation. Must be called only if
+  // IsGrowingIntoSingleGroupApplicable returned true.
+  void TransferSlotAfterSoo(CommonFields& c, size_t slot_size);
 
   // Shuffle control bits deterministically to the next capacity.
   // Returns offset for newly added element with given hash.
@@ -1726,6 +2171,13 @@ class HashSetResizeHelper {
   void GrowIntoSingleGroupShuffleControlBytes(ctrl_t* new_ctrl,
                                               size_t new_capacity) const;
 
+  // If the table was SOO, initializes new control bytes. `h2` is the control
+  // byte corresponding to the full slot. Must be called only if
+  // IsGrowingIntoSingleGroupApplicable returned true.
+  // Requires: `had_soo_slot_ || h2 == ctrl_t::kEmpty`.
+  void InitControlBytesAfterSoo(ctrl_t* new_ctrl, ctrl_t h2,
+                                size_t new_capacity);
+
   // Shuffle trivially transferable slots in the way consistent with
   // GrowIntoSingleGroupShuffleControlBytes.
   //
@@ -1739,8 +2191,7 @@ class HashSetResizeHelper {
   // 1. new_slots are transferred from old_slots_ consistent with
   //    GrowIntoSingleGroupShuffleControlBytes.
   // 2. Empty new_slots are *not* poisoned.
-  void GrowIntoSingleGroupShuffleTransferableSlots(void* old_slots,
-                                                   void* new_slots,
+  void GrowIntoSingleGroupShuffleTransferableSlots(void* new_slots,
                                                    size_t slot_size) const;
 
   // Poison empty slots that were transferred using the deterministic algorithm
@@ -1760,11 +2211,24 @@ class HashSetResizeHelper {
     }
   }
 
-  ctrl_t* old_ctrl_;
+  HeapOrSoo old_heap_or_soo_;
   size_t old_capacity_;
   bool had_infoz_;
+  bool was_soo_;
+  bool had_soo_slot_;
+  // Either null infoz or a pre-sampled forced infoz for SOO tables.
+  HashtablezInfoHandle forced_infoz_;
 };
 
+inline void PrepareInsertCommon(CommonFields& common) {
+  common.increment_size();
+  common.maybe_increment_generation_on_insert();
+}
+
+// Like prepare_insert, but for the case of inserting into a full SOO table.
+size_t PrepareInsertAfterSoo(size_t hash, size_t slot_size,
+                             CommonFields& common);
+
 // PolicyFunctions bundles together some information for a particular
 // raw_hash_set<T, ...> instantiation. This information is passed to
 // type-erased functions that want to do small amounts of type-specific
@@ -1772,21 +2236,29 @@ class HashSetResizeHelper {
 struct PolicyFunctions {
   size_t slot_size;
 
+  // Returns the pointer to the hash function stored in the set.
+  const void* (*hash_fn)(const CommonFields& common);
+
   // Returns the hash of the pointed-to slot.
-  size_t (*hash_slot)(void* set, void* slot);
+  size_t (*hash_slot)(const void* hash_fn, void* slot);
 
-  // Transfer the contents of src_slot to dst_slot.
+  // Transfers the contents of src_slot to dst_slot.
   void (*transfer)(void* set, void* dst_slot, void* src_slot);
 
-  // Deallocate the backing store from common.
+  // Deallocates the backing store from common.
   void (*dealloc)(CommonFields& common, const PolicyFunctions& policy);
+
+  // Resizes set to the new capacity.
+  // Arguments are used as in raw_hash_set::resize_impl.
+  void (*resize)(CommonFields& common, size_t new_capacity,
+                 HashtablezInfoHandle forced_infoz);
 };
 
 // ClearBackingArray clears the backing array, either modifying it in place,
 // or creating a new one based on the value of "reuse".
 // REQUIRES: c.capacity > 0
 void ClearBackingArray(CommonFields& c, const PolicyFunctions& policy,
-                       bool reuse);
+                       bool reuse, bool soo_enabled);
 
 // Type-erased version of raw_hash_set::erase_meta_only.
 void EraseMetaOnly(CommonFields& c, size_t index, size_t slot_size);
@@ -1817,9 +2289,26 @@ Y_ABSL_ATTRIBUTE_NOINLINE void TransferRelocatable(void*, void* dst, void* src)
   memcpy(dst, src, SizeOfSlot);
 }
 
-// Type-erased version of raw_hash_set::drop_deletes_without_resize.
-void DropDeletesWithoutResize(CommonFields& common,
-                              const PolicyFunctions& policy, void* tmp_space);
+// Type erased raw_hash_set::get_hash_ref_fn for the empty hash function case.
+const void* GetHashRefForEmptyHasher(const CommonFields& common);
+
+// Given the hash of a value not currently in the table and the first empty
+// slot in the probe sequence, finds a viable slot index to insert it at.
+//
+// In case there's no space left, the table can be resized or rehashed
+// (for tables with deleted slots, see FindInsertPositionWithGrowthOrRehash).
+//
+// In the case of absence of deleted slots and positive growth_left, the element
+// can be inserted in the provided `target` position.
+//
+// When the table has deleted slots (according to GrowthInfo), the target
+// position will be searched one more time using `find_first_non_full`.
+//
+// REQUIRES: Table is not SOO.
+// REQUIRES: At least one non-full slot available.
+// REQUIRES: `target` is a valid empty position to insert.
+size_t PrepareInsertNonSoo(CommonFields& common, size_t hash, FindInfo target,
+                           const PolicyFunctions& policy);
 
 // A SwissTable.
 //
@@ -1875,6 +2364,26 @@ class raw_hash_set {
   using key_arg = typename KeyArgImpl::template type<K, key_type>;
 
  private:
+  // TODO(b/289225379): we could add extra SOO space inside raw_hash_set
+  // after CommonFields to allow inlining larger slot_types (e.g. TString),
+  // but it's a bit complicated if we want to support incomplete mapped_type in
+  // flat_hash_map. We could potentially do this for flat_hash_set and for an
+  // allowlist of `mapped_type`s of flat_hash_map that includes e.g. arithmetic
+  // types, strings, cords, and pairs/tuples of allowlisted types.
+  constexpr static bool SooEnabled() {
+    return PolicyTraits::soo_enabled() &&
+           sizeof(slot_type) <= sizeof(HeapOrSoo) &&
+           alignof(slot_type) <= alignof(HeapOrSoo);
+  }
+
+  // Whether `size` fits in the SOO capacity of this table.
+  bool fits_in_soo(size_t size) const {
+    return SooEnabled() && size <= SooCapacity();
+  }
+  // Whether this table is in SOO mode or non-SOO mode.
+  bool is_soo() const { return fits_in_soo(capacity()); }
+  bool is_full_soo() const { return is_soo() && !empty(); }
+
   // Give an early error when key_type is not hashable/eq.
   auto KeyTypeCanBeHashed(const Hash& h, const key_type& k) -> decltype(h(k));
   auto KeyTypeCanBeEq(const Eq& eq, const key_type& k) -> decltype(eq(k, k));
@@ -1928,6 +2437,7 @@ class raw_hash_set {
 
   class iterator : private HashSetIteratorGenerationInfo {
     friend class raw_hash_set;
+    friend struct HashtableFreeFunctionsAccess;
 
    public:
     using iterator_category = std::forward_iterator_tag;
@@ -1958,6 +2468,7 @@ class raw_hash_set {
       ++ctrl_;
       ++slot_;
       skip_empty_or_deleted();
+      if (Y_ABSL_PREDICT_FALSE(*ctrl_ == ctrl_t::kSentinel)) ctrl_ = nullptr;
       return *this;
     }
     // PRECONDITION: not an end() iterator.
@@ -1988,22 +2499,31 @@ class raw_hash_set {
       // not equal to any end iterator.
       Y_ABSL_ASSUME(ctrl != nullptr);
     }
+    // This constructor is used in begin() to avoid an MSan
+    // use-of-uninitialized-value error. Delegating from this constructor to
+    // the previous one doesn't avoid the error.
+    iterator(ctrl_t* ctrl, MaybeInitializedPtr slot,
+             const GenerationType* generation_ptr)
+        : HashSetIteratorGenerationInfo(generation_ptr),
+          ctrl_(ctrl),
+          slot_(to_slot(slot.get())) {
+      // This assumption helps the compiler know that any non-end iterator is
+      // not equal to any end iterator.
+      Y_ABSL_ASSUME(ctrl != nullptr);
+    }
     // For end() iterators.
     explicit iterator(const GenerationType* generation_ptr)
         : HashSetIteratorGenerationInfo(generation_ptr), ctrl_(nullptr) {}
 
-    // Fixes up `ctrl_` to point to a full by advancing it and `slot_` until
-    // they reach one.
-    //
-    // If a sentinel is reached, we null `ctrl_` out instead.
+    // Fixes up `ctrl_` to point to a full or sentinel by advancing `ctrl_` and
+    // `slot_` until they reach one.
     void skip_empty_or_deleted() {
       while (IsEmptyOrDeleted(*ctrl_)) {
         uint32_t shift =
-            GroupEmptyOrDeleted{ctrl_}.CountLeadingEmptyOrDeleted();
+            GroupFullEmptyOrDeleted{ctrl_}.CountLeadingEmptyOrDeleted();
         ctrl_ += shift;
         slot_ += shift;
       }
-      if (Y_ABSL_PREDICT_FALSE(*ctrl_ == ctrl_t::kSentinel)) ctrl_ = nullptr;
     }
 
     ctrl_t* control() const { return ctrl_; }
@@ -2091,8 +2611,9 @@ class raw_hash_set {
       size_t bucket_count, const hasher& hash = hasher(),
       const key_equal& eq = key_equal(),
       const allocator_type& alloc = allocator_type())
-      : settings_(CommonFields{}, hash, eq, alloc) {
-    if (bucket_count) {
+      : settings_(CommonFields::CreateDefault<SooEnabled()>(), hash, eq,
+                  alloc) {
+    if (bucket_count > (SooEnabled() ? SooCapacity() : 0)) {
       resize(NormalizeCapacity(bucket_count));
     }
   }
@@ -2193,22 +2714,69 @@ class raw_hash_set {
                                that.alloc_ref())) {}
 
   raw_hash_set(const raw_hash_set& that, const allocator_type& a)
-      : raw_hash_set(0, that.hash_ref(), that.eq_ref(), a) {
+      : raw_hash_set(GrowthToLowerboundCapacity(that.size()), that.hash_ref(),
+                     that.eq_ref(), a) {
     const size_t size = that.size();
-    if (size == 0) return;
-    reserve(size);
-    // Because the table is guaranteed to be empty, we can do something faster
-    // than a full `insert`.
-    for (const auto& v : that) {
-      const size_t hash = PolicyTraits::apply(HashElement{hash_ref()}, v);
-      auto target = find_first_non_full_outofline(common(), hash);
-      SetCtrl(common(), target.offset, H2(hash), sizeof(slot_type));
-      emplace_at(target.offset, v);
-      common().maybe_increment_generation_on_insert();
-      infoz().RecordInsert(hash, target.probe_length);
+    if (size == 0) {
+      return;
+    }
+    // We don't use `that.is_soo()` here because `that` can have non-SOO
+    // capacity but have a size that fits into SOO capacity.
+    if (fits_in_soo(size)) {
+      assert(size == 1);
+      common().set_full_soo();
+      emplace_at(soo_iterator(), *that.begin());
+      const HashtablezInfoHandle infoz = try_sample_soo();
+      if (infoz.IsSampled()) resize_with_soo_infoz(infoz);
+      return;
+    }
+    assert(!that.is_soo());
+    const size_t cap = capacity();
+    // Note about single group tables:
+    // 1. It is correct to have any order of elements.
+    // 2. Order has to be non deterministic.
+    // 3. We are assigning elements with arbitrary `shift` starting from
+    //    `capacity + shift` position.
+    // 4. `shift` must be coprime with `capacity + 1` in order to be able to use
+    //     modular arithmetic to traverse all positions, instead if cycling
+    //     through a subset of positions. Odd numbers are coprime with any
+    //     `capacity + 1` (2^N).
+    size_t offset = cap;
+    const size_t shift =
+        is_single_group(cap) ? (PerTableSalt(control()) | 1) : 0;
+    IterateOverFullSlots(
+        that.common(), that.slot_array(),
+        [&](const ctrl_t* that_ctrl,
+            slot_type* that_slot) Y_ABSL_ATTRIBUTE_ALWAYS_INLINE {
+          if (shift == 0) {
+            // Big tables case. Position must be searched via probing.
+            // The table is guaranteed to be empty, so we can do faster than
+            // a full `insert`.
+            const size_t hash = PolicyTraits::apply(
+                HashElement{hash_ref()}, PolicyTraits::element(that_slot));
+            FindInfo target = find_first_non_full_outofline(common(), hash);
+            infoz().RecordInsert(hash, target.probe_length);
+            offset = target.offset;
+          } else {
+            // Small tables case. Next position is computed via shift.
+            offset = (offset + shift) & cap;
+          }
+          const h2_t h2 = static_cast<h2_t>(*that_ctrl);
+          assert(  // We rely that hash is not changed for small tables.
+              H2(PolicyTraits::apply(HashElement{hash_ref()},
+                                     PolicyTraits::element(that_slot))) == h2 &&
+              "hash function value changed unexpectedly during the copy");
+          SetCtrl(common(), offset, h2, sizeof(slot_type));
+          emplace_at(iterator_at(offset), PolicyTraits::element(that_slot));
+          common().maybe_increment_generation_on_insert();
+        });
+    if (shift != 0) {
+      // On small table copy we do not record individual inserts.
+      // RecordInsert requires hash, but it is unknown for small tables.
+      infoz().RecordStorageChanged(size, cap);
     }
     common().set_size(size);
-    set_growth_left(growth_left() - size);
+    growth_info().OverwriteManyEmptyAsFull(size);
   }
 
   Y_ABSL_ATTRIBUTE_NOINLINE raw_hash_set(raw_hash_set&& that) noexcept(
@@ -2220,16 +2788,22 @@ class raw_hash_set {
          // would create a nullptr functor that cannot be called.
          // TODO(b/296061262): move instead of copying hash/eq/alloc.
          // Note: we avoid using exchange for better generated code.
-        settings_(std::move(that.common()), that.hash_ref(), that.eq_ref(),
-                  that.alloc_ref()) {
-    that.common() = CommonFields{};
+        settings_(PolicyTraits::transfer_uses_memcpy() || !that.is_full_soo()
+                      ? std::move(that.common())
+                      : CommonFields{full_soo_tag_t{}},
+                  that.hash_ref(), that.eq_ref(), that.alloc_ref()) {
+    if (!PolicyTraits::transfer_uses_memcpy() && that.is_full_soo()) {
+      transfer(soo_slot(), that.soo_slot());
+    }
+    that.common() = CommonFields::CreateDefault<SooEnabled()>();
     maybe_increment_generation_or_rehash_on_move();
   }
 
   raw_hash_set(raw_hash_set&& that, const allocator_type& a)
-      : settings_(CommonFields{}, that.hash_ref(), that.eq_ref(), a) {
+      : settings_(CommonFields::CreateDefault<SooEnabled()>(), that.hash_ref(),
+                  that.eq_ref(), a) {
     if (a == that.alloc_ref()) {
-      std::swap(common(), that.common());
+      swap_common(that);
       maybe_increment_generation_or_rehash_on_move();
     } else {
       move_elements_allocs_unequal(std::move(that));
@@ -2264,8 +2838,12 @@ class raw_hash_set {
   ~raw_hash_set() { destructor_impl(); }
 
   iterator begin() Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
-    auto it = iterator_at(0);
+    if (Y_ABSL_PREDICT_FALSE(empty())) return end();
+    if (is_soo()) return soo_iterator();
+    iterator it = {control(), common().slots_union(),
+                   common().generation_ptr()};
     it.skip_empty_or_deleted();
+    assert(IsFull(*it.control()));
     return it;
   }
   iterator end() Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
@@ -2285,7 +2863,14 @@ class raw_hash_set {
 
   bool empty() const { return !size(); }
   size_t size() const { return common().size(); }
-  size_t capacity() const { return common().capacity(); }
+  size_t capacity() const {
+    const size_t cap = common().capacity();
+    // Compiler complains when using functions in assume so use local variables.
+    Y_ABSL_ATTRIBUTE_UNUSED static constexpr bool kEnabled = SooEnabled();
+    Y_ABSL_ATTRIBUTE_UNUSED static constexpr size_t kCapacity = SooCapacity();
+    Y_ABSL_ASSUME(!kEnabled || cap >= kCapacity);
+    return cap;
+  }
   size_t max_size() const { return (std::numeric_limits<size_t>::max)(); }
 
   Y_ABSL_ATTRIBUTE_REINITIALIZES void clear() {
@@ -2299,9 +2884,13 @@ class raw_hash_set {
     const size_t cap = capacity();
     if (cap == 0) {
       // Already guaranteed to be empty; so nothing to do.
+    } else if (is_soo()) {
+      if (!empty()) destroy(soo_slot());
+      common().set_empty_soo();
     } else {
       destroy_slots();
-      ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/cap < 128);
+      ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/cap < 128,
+                        SooEnabled());
     }
     common().set_reserved_growth(0);
     common().set_reservation_size(0);
@@ -2432,7 +3021,7 @@ class raw_hash_set {
   std::pair<iterator, bool> emplace(Args&&... args)
       Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
     alignas(slot_type) unsigned char raw[sizeof(slot_type)];
-    slot_type* slot = reinterpret_cast<slot_type*>(&raw);
+    slot_type* slot = to_slot(&raw);
 
     construct(slot, std::forward<Args>(args)...);
     const auto& elem = PolicyTraits::element(slot);
@@ -2496,11 +3085,11 @@ class raw_hash_set {
                         F&& f) Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
     auto res = find_or_prepare_insert(key);
     if (res.second) {
-      slot_type* slot = slot_array() + res.first;
+      slot_type* slot = res.first.slot();
       std::forward<F>(f)(constructor(&alloc_ref(), &slot));
       assert(!slot);
     }
-    return iterator_at(res.first);
+    return res.first;
   }
 
   // Extension API: support for heterogeneous keys.
@@ -2524,7 +3113,7 @@ class raw_hash_set {
   // this method returns void to reduce algorithmic complexity to O(1).  The
   // iterator is invalidated, so any increment should be done before calling
   // erase.  In order to erase while iterating across a map, use the following
-  // idiom (which also works for standard containers):
+  // idiom (which also works for some standard containers):
   //
   // for (auto it = m.begin(), end = m.end(); it != end;) {
   //   // `erase()` will invalidate `it`, so advance `it` first.
@@ -2540,7 +3129,11 @@ class raw_hash_set {
   void erase(iterator it) {
     AssertIsFull(it.control(), it.generation(), it.generation_ptr(), "erase()");
     destroy(it.slot());
-    erase_meta_only(it);
+    if (is_soo()) {
+      common().set_empty_soo();
+    } else {
+      erase_meta_only(it);
+    }
   }
 
   iterator erase(const_iterator first,
@@ -2548,12 +3141,19 @@ class raw_hash_set {
     // We check for empty first because ClearBackingArray requires that
     // capacity() > 0 as a precondition.
     if (empty()) return end();
+    if (first == last) return last.inner_;
+    if (is_soo()) {
+      destroy(soo_slot());
+      common().set_empty_soo();
+      return end();
+    }
     if (first == begin() && last == end()) {
       // TODO(ezb): we access control bytes in destroy_slots so it could make
       // sense to combine destroy_slots and ClearBackingArray to avoid cache
       // misses when the table is large. Note that we also do this in clear().
       destroy_slots();
-      ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/true);
+      ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/true,
+                        SooEnabled());
       common().set_reserved_growth(common().reservation_size());
       return end();
     }
@@ -2568,13 +3168,21 @@ class raw_hash_set {
   template <typename H, typename E>
   void merge(raw_hash_set<Policy, H, E, Alloc>& src) {  // NOLINT
     assert(this != &src);
+    // Returns whether insertion took place.
+    const auto insert_slot = [this](slot_type* src_slot) {
+      return PolicyTraits::apply(InsertSlot<false>{*this, std::move(*src_slot)},
+                                 PolicyTraits::element(src_slot))
+          .second;
+    };
+
+    if (src.is_soo()) {
+      if (src.empty()) return;
+      if (insert_slot(src.soo_slot())) src.common().set_empty_soo();
+      return;
+    }
     for (auto it = src.begin(), e = src.end(); it != e;) {
       auto next = std::next(it);
-      if (PolicyTraits::apply(InsertSlot<false>{*this, std::move(*it.slot())},
-                              PolicyTraits::element(it.slot()))
-              .second) {
-        src.erase_meta_only(it);
-      }
+      if (insert_slot(it.slot())) src.erase_meta_only(it);
       it = next;
     }
   }
@@ -2588,7 +3196,11 @@ class raw_hash_set {
     AssertIsFull(position.control(), position.inner_.generation(),
                  position.inner_.generation_ptr(), "extract()");
     auto node = CommonAccess::Transfer<node_type>(alloc_ref(), position.slot());
-    erase_meta_only(position);
+    if (is_soo()) {
+      common().set_empty_soo();
+    } else {
+      erase_meta_only(position);
+    }
     return node;
   }
 
@@ -2605,7 +3217,7 @@ class raw_hash_set {
       IsNoThrowSwappable<allocator_type>(
           typename AllocTraits::propagate_on_container_swap{})) {
     using std::swap;
-    swap(common(), that.common());
+    swap_common(that);
     swap(hash_ref(), that.hash_ref());
     swap(eq_ref(), that.eq_ref());
     SwapAlloc(alloc_ref(), that.alloc_ref(),
@@ -2613,17 +3225,41 @@ class raw_hash_set {
   }
 
   void rehash(size_t n) {
-    if (n == 0 && capacity() == 0) return;
-    if (n == 0 && size() == 0) {
-      ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/false);
-      return;
+    const size_t cap = capacity();
+    if (n == 0) {
+      if (cap == 0 || is_soo()) return;
+      if (empty()) {
+        ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/false,
+                          SooEnabled());
+        return;
+      }
+      if (fits_in_soo(size())) {
+        // When the table is already sampled, we keep it sampled.
+        if (infoz().IsSampled()) {
+          const size_t kInitialSampledCapacity = NextCapacity(SooCapacity());
+          if (capacity() > kInitialSampledCapacity) {
+            resize(kInitialSampledCapacity);
+          }
+          // This asserts that we didn't lose sampling coverage in `resize`.
+          assert(infoz().IsSampled());
+          return;
+        }
+        alignas(slot_type) unsigned char slot_space[sizeof(slot_type)];
+        slot_type* tmp_slot = to_slot(slot_space);
+        transfer(tmp_slot, begin().slot());
+        ClearBackingArray(common(), GetPolicyFunctions(), /*reuse=*/false,
+                          SooEnabled());
+        transfer(soo_slot(), tmp_slot);
+        common().set_full_soo();
+        return;
+      }
     }
 
     // bitor is a faster way of doing `max` here. We will round up to the next
     // power-of-2-minus-1, so bitor is good enough.
     auto m = NormalizeCapacity(n | GrowthToLowerboundCapacity(size()));
     // n == 0 unconditionally rehashes as per the standard.
-    if (n == 0 || m > capacity()) {
+    if (n == 0 || m > cap) {
       resize(m);
 
       // This is after resize, to ensure that we have completed the allocation
@@ -2633,7 +3269,9 @@ class raw_hash_set {
   }
 
   void reserve(size_t n) {
-    if (n > size() + growth_left()) {
+    const size_t max_size_before_growth =
+        is_soo() ? SooCapacity() : size() + growth_left();
+    if (n > max_size_before_growth) {
       size_t m = GrowthToLowerboundCapacity(n);
       resize(NormalizeCapacity(m));
 
@@ -2666,6 +3304,7 @@ class raw_hash_set {
   // specific benchmarks indicating its importance.
   template <class K = key_type>
   void prefetch(const key_arg<K>& key) const {
+    if (SooEnabled() ? is_soo() : capacity() == 0) return;
     (void)key;
     // Avoid probing if we won't be able to prefetch the addresses received.
 #ifdef Y_ABSL_HAVE_PREFETCH
@@ -2686,26 +3325,16 @@ class raw_hash_set {
   template <class K = key_type>
   iterator find(const key_arg<K>& key,
                 size_t hash) Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
-    auto seq = probe(common(), hash);
-    slot_type* slot_ptr = slot_array();
-    const ctrl_t* ctrl = control();
-    while (true) {
-      Group g{ctrl + seq.offset()};
-      for (uint32_t i : g.Match(H2(hash))) {
-        if (Y_ABSL_PREDICT_TRUE(PolicyTraits::apply(
-                EqualElement<K>{key, eq_ref()},
-                PolicyTraits::element(slot_ptr + seq.offset(i)))))
-          return iterator_at(seq.offset(i));
-      }
-      if (Y_ABSL_PREDICT_TRUE(g.MaskEmpty())) return end();
-      seq.next();
-      assert(seq.index() <= capacity() && "full table!");
-    }
+    AssertHashEqConsistent(key);
+    if (is_soo()) return find_soo(key);
+    return find_non_soo(key, hash);
   }
   template <class K = key_type>
   iterator find(const key_arg<K>& key) Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    AssertHashEqConsistent(key);
+    if (is_soo()) return find_soo(key);
     prefetch_heap_block();
-    return find(key, hash_ref()(key));
+    return find_non_soo(key, hash_ref()(key));
   }
 
   template <class K = key_type>
@@ -2716,8 +3345,7 @@ class raw_hash_set {
   template <class K = key_type>
   const_iterator find(const key_arg<K>& key) const
       Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
-    prefetch_heap_block();
-    return find(key, hash_ref()(key));
+    return const_cast<raw_hash_set*>(this)->find(key);
   }
 
   template <class K = key_type>
@@ -2791,6 +3419,8 @@ class raw_hash_set {
   friend struct y_absl::container_internal::hashtable_debug_internal::
       HashtableDebugAccess;
 
+  friend struct y_absl::container_internal::HashtableFreeFunctionsAccess;
+
   struct FindElement {
     template <class K, class... Args>
     const_iterator operator()(const K& key, Args&&...) const {
@@ -2824,7 +3454,7 @@ class raw_hash_set {
       if (res.second) {
         s.emplace_at(res.first, std::forward<Args>(args)...);
       }
-      return {s.iterator_at(res.first), res.second};
+      return res;
     }
     raw_hash_set& s;
   };
@@ -2835,11 +3465,11 @@ class raw_hash_set {
     std::pair<iterator, bool> operator()(const K& key, Args&&...) && {
       auto res = s.find_or_prepare_insert(key);
       if (res.second) {
-        s.transfer(s.slot_array() + res.first, &slot);
+        s.transfer(res.first.slot(), &slot);
       } else if (do_destroy) {
         s.destroy(&slot);
       }
-      return {s.iterator_at(res.first), res.second};
+      return res;
     }
     raw_hash_set& s;
     // Constructed slot. Either moved into place or destroyed.
@@ -2858,17 +3488,55 @@ class raw_hash_set {
     PolicyTraits::transfer(&alloc_ref(), to, from);
   }
 
-  inline void destroy_slots() {
-    const size_t cap = capacity();
+  // TODO(b/289225379): consider having a helper class that has the impls for
+  // SOO functionality.
+  template <class K = key_type>
+  iterator find_soo(const key_arg<K>& key) {
+    assert(is_soo());
+    return empty() || !PolicyTraits::apply(EqualElement<K>{key, eq_ref()},
+                                           PolicyTraits::element(soo_slot()))
+               ? end()
+               : soo_iterator();
+  }
+
+  template <class K = key_type>
+  iterator find_non_soo(const key_arg<K>& key, size_t hash) {
+    assert(!is_soo());
+    auto seq = probe(common(), hash);
     const ctrl_t* ctrl = control();
-    slot_type* slot = slot_array();
-    for (size_t i = 0; i != cap; ++i) {
-      if (IsFull(ctrl[i])) {
-        destroy(slot + i);
+    while (true) {
+      Group g{ctrl + seq.offset()};
+      for (uint32_t i : g.Match(H2(hash))) {
+        if (Y_ABSL_PREDICT_TRUE(PolicyTraits::apply(
+                EqualElement<K>{key, eq_ref()},
+                PolicyTraits::element(slot_array() + seq.offset(i)))))
+          return iterator_at(seq.offset(i));
       }
+      if (Y_ABSL_PREDICT_TRUE(g.MaskEmpty())) return end();
+      seq.next();
+      assert(seq.index() <= capacity() && "full table!");
     }
   }
 
+  // Conditionally samples hashtablez for SOO tables. This should be called on
+  // insertion into an empty SOO table and in copy construction when the size
+  // can fit in SOO capacity.
+  inline HashtablezInfoHandle try_sample_soo() {
+    assert(is_soo());
+    if (!ShouldSampleHashtablezInfo<CharAlloc>()) return HashtablezInfoHandle{};
+    return Sample(sizeof(slot_type), sizeof(key_type), sizeof(value_type),
+                  SooCapacity());
+  }
+
+  inline void destroy_slots() {
+    assert(!is_soo());
+    if (PolicyTraits::template destroy_is_trivial<Alloc>()) return;
+    IterateOverFullSlots(
+        common(), slot_array(),
+        [&](const ctrl_t*, slot_type* slot)
+            Y_ABSL_ATTRIBUTE_ALWAYS_INLINE { this->destroy(slot); });
+  }
+
   inline void dealloc() {
     assert(capacity() != 0);
     // Unpoison before returning the memory to the allocator.
@@ -2881,6 +3549,12 @@ class raw_hash_set {
 
   inline void destructor_impl() {
     if (capacity() == 0) return;
+    if (is_soo()) {
+      if (!empty()) {
+        Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED(destroy(soo_slot()));
+      }
+      return;
+    }
     destroy_slots();
     dealloc();
   }
@@ -2890,10 +3564,16 @@ class raw_hash_set {
   // This merely updates the pertinent control byte. This can be used in
   // conjunction with Policy::transfer to move the object to another place.
   void erase_meta_only(const_iterator it) {
+    assert(!is_soo());
     EraseMetaOnly(common(), static_cast<size_t>(it.control() - control()),
                   sizeof(slot_type));
   }
 
+  size_t hash_of(slot_type* slot) const {
+    return PolicyTraits::apply(HashElement{hash_ref()},
+                               PolicyTraits::element(slot));
+  }
+
   // Resizes table to the new capacity and move all elements to the new
   // positions accordingly.
   //
@@ -2902,143 +3582,165 @@ class raw_hash_set {
   // HashSetResizeHelper::FindFirstNonFullAfterResize(
   //    common(), old_capacity, hash)
   // can be called right after `resize`.
-  Y_ABSL_ATTRIBUTE_NOINLINE void resize(size_t new_capacity) {
+  void resize(size_t new_capacity) {
+    raw_hash_set::resize_impl(common(), new_capacity, HashtablezInfoHandle{});
+  }
+
+  // As above, except that we also accept a pre-sampled, forced infoz for
+  // SOO tables, since they need to switch from SOO to heap in order to
+  // store the infoz.
+  void resize_with_soo_infoz(HashtablezInfoHandle forced_infoz) {
+    assert(forced_infoz.IsSampled());
+    raw_hash_set::resize_impl(common(), NextCapacity(SooCapacity()),
+                              forced_infoz);
+  }
+
+  // Resizes set to the new capacity.
+  // It is a static function in order to use its pointer in GetPolicyFunctions.
+  Y_ABSL_ATTRIBUTE_NOINLINE static void resize_impl(
+      CommonFields& common, size_t new_capacity,
+      HashtablezInfoHandle forced_infoz) {
+    raw_hash_set* set = reinterpret_cast<raw_hash_set*>(&common);
     assert(IsValidCapacity(new_capacity));
-    HashSetResizeHelper resize_helper(common());
-    auto* old_slots = slot_array();
-    common().set_capacity(new_capacity);
+    assert(!set->fits_in_soo(new_capacity));
+    const bool was_soo = set->is_soo();
+    const bool had_soo_slot = was_soo && !set->empty();
+    const ctrl_t soo_slot_h2 =
+        had_soo_slot ? static_cast<ctrl_t>(H2(set->hash_of(set->soo_slot())))
+                     : ctrl_t::kEmpty;
+    HashSetResizeHelper resize_helper(common, was_soo, had_soo_slot,
+                                      forced_infoz);
+    // Initialize HashSetResizeHelper::old_heap_or_soo_. We can't do this in
+    // HashSetResizeHelper constructor because it can't transfer slots when
+    // transfer_uses_memcpy is false.
+    // TODO(b/289225379): try to handle more of the SOO cases inside
+    // InitializeSlots. See comment on cl/555990034 snapshot #63.
+    if (PolicyTraits::transfer_uses_memcpy() || !had_soo_slot) {
+      resize_helper.old_heap_or_soo() = common.heap_or_soo();
+    } else {
+      set->transfer(set->to_slot(resize_helper.old_soo_data()),
+                    set->soo_slot());
+    }
+    common.set_capacity(new_capacity);
     // Note that `InitializeSlots` does different number initialization steps
     // depending on the values of `transfer_uses_memcpy` and capacities.
     // Refer to the comment in `InitializeSlots` for more details.
     const bool grow_single_group =
         resize_helper.InitializeSlots<CharAlloc, sizeof(slot_type),
                                       PolicyTraits::transfer_uses_memcpy(),
-                                      alignof(slot_type)>(
-            common(), const_cast<std::remove_const_t<slot_type>*>(old_slots),
-            CharAlloc(alloc_ref()));
+                                      SooEnabled(), alignof(slot_type)>(
+            common, CharAlloc(set->alloc_ref()), soo_slot_h2, sizeof(key_type),
+            sizeof(value_type));
 
-    if (resize_helper.old_capacity() == 0) {
+    // In the SooEnabled() case, capacity is never 0 so we don't check.
+    if (!SooEnabled() && resize_helper.old_capacity() == 0) {
       // InitializeSlots did all the work including infoz().RecordRehash().
       return;
     }
+    assert(resize_helper.old_capacity() > 0);
+    // Nothing more to do in this case.
+    if (was_soo && !had_soo_slot) return;
 
+    slot_type* new_slots = set->slot_array();
     if (grow_single_group) {
       if (PolicyTraits::transfer_uses_memcpy()) {
         // InitializeSlots did all the work.
         return;
       }
-      // We want GrowSizeIntoSingleGroup to be called here in order to make
-      // InitializeSlots not depend on PolicyTraits.
-      resize_helper.GrowSizeIntoSingleGroup<PolicyTraits>(common(), alloc_ref(),
-                                                          old_slots);
+      if (was_soo) {
+        set->transfer(new_slots + resize_helper.SooSlotIndex(),
+                      to_slot(resize_helper.old_soo_data()));
+        return;
+      } else {
+        // We want GrowSizeIntoSingleGroup to be called here in order to make
+        // InitializeSlots not depend on PolicyTraits.
+        resize_helper.GrowSizeIntoSingleGroup<PolicyTraits>(common,
+                                                            set->alloc_ref());
+      }
     } else {
       // InitializeSlots prepares control bytes to correspond to empty table.
-      auto* new_slots = slot_array();
-      size_t total_probe_length = 0;
-      for (size_t i = 0; i != resize_helper.old_capacity(); ++i) {
-        if (IsFull(resize_helper.old_ctrl()[i])) {
-          size_t hash = PolicyTraits::apply(
-              HashElement{hash_ref()}, PolicyTraits::element(old_slots + i));
-          auto target = find_first_non_full(common(), hash);
-          size_t new_i = target.offset;
-          total_probe_length += target.probe_length;
-          SetCtrl(common(), new_i, H2(hash), sizeof(slot_type));
-          transfer(new_slots + new_i, old_slots + i);
+      const auto insert_slot = [&](slot_type* slot) {
+        size_t hash = PolicyTraits::apply(HashElement{set->hash_ref()},
+                                          PolicyTraits::element(slot));
+        auto target = find_first_non_full(common, hash);
+        SetCtrl(common, target.offset, H2(hash), sizeof(slot_type));
+        set->transfer(new_slots + target.offset, slot);
+        return target.probe_length;
+      };
+      if (was_soo) {
+        insert_slot(to_slot(resize_helper.old_soo_data()));
+        return;
+      } else {
+        auto* old_slots = static_cast<slot_type*>(resize_helper.old_slots());
+        size_t total_probe_length = 0;
+        for (size_t i = 0; i != resize_helper.old_capacity(); ++i) {
+          if (IsFull(resize_helper.old_ctrl()[i])) {
+            total_probe_length += insert_slot(old_slots + i);
+          }
         }
+        common.infoz().RecordRehash(total_probe_length);
       }
-      infoz().RecordRehash(total_probe_length);
     }
-    resize_helper.DeallocateOld<alignof(slot_type)>(
-        CharAlloc(alloc_ref()), sizeof(slot_type),
-        const_cast<std::remove_const_t<slot_type>*>(old_slots));
+    resize_helper.DeallocateOld<alignof(slot_type)>(CharAlloc(set->alloc_ref()),
+                                                    sizeof(slot_type));
   }
 
-  // Prunes control bytes to remove as many tombstones as possible.
-  //
-  // See the comment on `rehash_and_grow_if_necessary()`.
-  inline void drop_deletes_without_resize() {
-    // Stack-allocate space for swapping elements.
-    alignas(slot_type) unsigned char tmp[sizeof(slot_type)];
-    DropDeletesWithoutResize(common(), GetPolicyFunctions(), tmp);
-  }
+  // Casting directly from e.g. char* to slot_type* can cause compilation errors
+  // on objective-C. This function converts to void* first, avoiding the issue.
+  static slot_type* to_slot(void* buf) { return static_cast<slot_type*>(buf); }
 
-  // Called whenever the table *might* need to conditionally grow.
-  //
-  // This function is an optimization opportunity to perform a rehash even when
-  // growth is unnecessary, because vacating tombstones is beneficial for
-  // performance in the long-run.
-  void rehash_and_grow_if_necessary() {
-    const size_t cap = capacity();
-    if (cap > Group::kWidth &&
-        // Do these calculations in 64-bit to avoid overflow.
-        size() * uint64_t{32} <= cap * uint64_t{25}) {
-      // Squash DELETED without growing if there is enough capacity.
-      //
-      // Rehash in place if the current size is <= 25/32 of capacity.
-      // Rationale for such a high factor: 1) drop_deletes_without_resize() is
-      // faster than resize, and 2) it takes quite a bit of work to add
-      // tombstones.  In the worst case, seems to take approximately 4
-      // insert/erase pairs to create a single tombstone and so if we are
-      // rehashing because of tombstones, we can afford to rehash-in-place as
-      // long as we are reclaiming at least 1/8 the capacity without doing more
-      // than 2X the work.  (Where "work" is defined to be size() for rehashing
-      // or rehashing in place, and 1 for an insert or erase.)  But rehashing in
-      // place is faster per operation than inserting or even doubling the size
-      // of the table, so we actually afford to reclaim even less space from a
-      // resize-in-place.  The decision is to rehash in place if we can reclaim
-      // at about 1/8th of the usable capacity (specifically 3/28 of the
-      // capacity) which means that the total cost of rehashing will be a small
-      // fraction of the total work.
-      //
-      // Here is output of an experiment using the BM_CacheInSteadyState
-      // benchmark running the old case (where we rehash-in-place only if we can
-      // reclaim at least 7/16*capacity) vs. this code (which rehashes in place
-      // if we can recover 3/32*capacity).
-      //
-      // Note that although in the worst-case number of rehashes jumped up from
-      // 15 to 190, but the number of operations per second is almost the same.
-      //
-      // Abridged output of running BM_CacheInSteadyState benchmark from
-      // raw_hash_set_benchmark.   N is the number of insert/erase operations.
-      //
-      //      | OLD (recover >= 7/16        | NEW (recover >= 3/32)
-      // size |    N/s LoadFactor NRehashes |    N/s LoadFactor NRehashes
-      //  448 | 145284       0.44        18 | 140118       0.44        19
-      //  493 | 152546       0.24        11 | 151417       0.48        28
-      //  538 | 151439       0.26        11 | 151152       0.53        38
-      //  583 | 151765       0.28        11 | 150572       0.57        50
-      //  628 | 150241       0.31        11 | 150853       0.61        66
-      //  672 | 149602       0.33        12 | 150110       0.66        90
-      //  717 | 149998       0.35        12 | 149531       0.70       129
-      //  762 | 149836       0.37        13 | 148559       0.74       190
-      //  807 | 149736       0.39        14 | 151107       0.39        14
-      //  852 | 150204       0.42        15 | 151019       0.42        15
-      drop_deletes_without_resize();
+  // Requires that lhs does not have a full SOO slot.
+  static void move_common(bool that_is_full_soo, allocator_type& rhs_alloc,
+                          CommonFields& lhs, CommonFields&& rhs) {
+    if (PolicyTraits::transfer_uses_memcpy() || !that_is_full_soo) {
+      lhs = std::move(rhs);
     } else {
-      // Otherwise grow the container.
-      resize(NextCapacity(cap));
+      lhs.move_non_heap_or_soo_fields(rhs);
+      // TODO(b/303305702): add reentrancy guard.
+      PolicyTraits::transfer(&rhs_alloc, to_slot(lhs.soo_data()),
+                             to_slot(rhs.soo_data()));
     }
   }
 
+  // Swaps common fields making sure to avoid memcpy'ing a full SOO slot if we
+  // aren't allowed to do so.
+  void swap_common(raw_hash_set& that) {
+    using std::swap;
+    if (PolicyTraits::transfer_uses_memcpy()) {
+      swap(common(), that.common());
+      return;
+    }
+    CommonFields tmp = CommonFields::CreateDefault<SooEnabled()>();
+    const bool that_is_full_soo = that.is_full_soo();
+    move_common(that_is_full_soo, that.alloc_ref(), tmp,
+                std::move(that.common()));
+    move_common(is_full_soo(), alloc_ref(), that.common(), std::move(common()));
+    move_common(that_is_full_soo, that.alloc_ref(), common(), std::move(tmp));
+  }
+
   void maybe_increment_generation_or_rehash_on_move() {
-    common().maybe_increment_generation_on_move();
+    if (!SwisstableGenerationsEnabled() || capacity() == 0 || is_soo()) {
+      return;
+    }
+    common().increment_generation();
     if (!empty() && common().should_rehash_for_bug_detection_on_move()) {
       resize(capacity());
     }
   }
 
-  template<bool propagate_alloc>
+  template <bool propagate_alloc>
   raw_hash_set& assign_impl(raw_hash_set&& that) {
     // We don't bother checking for this/that aliasing. We just need to avoid
     // breaking the invariants in that case.
     destructor_impl();
-    common() = std::move(that.common());
+    move_common(that.is_full_soo(), that.alloc_ref(), common(),
+                std::move(that.common()));
     // TODO(b/296061262): move instead of copying hash/eq/alloc.
     hash_ref() = that.hash_ref();
     eq_ref() = that.eq_ref();
     CopyAlloc(alloc_ref(), that.alloc_ref(),
               std::integral_constant<bool, propagate_alloc>());
-    that.common() = CommonFields{};
+    that.common() = CommonFields::CreateDefault<SooEnabled()>();
     maybe_increment_generation_or_rehash_on_move();
     return *this;
   }
@@ -3051,8 +3753,8 @@ class raw_hash_set {
       insert(std::move(PolicyTraits::element(it.slot())));
       that.destroy(it.slot());
     }
-    that.dealloc();
-    that.common() = CommonFields{};
+    if (!that.is_soo()) that.dealloc();
+    that.common() = CommonFields::CreateDefault<SooEnabled()>();
     maybe_increment_generation_or_rehash_on_move();
     return *this;
   }
@@ -3078,12 +3780,30 @@ class raw_hash_set {
     return move_elements_allocs_unequal(std::move(that));
   }
 
- protected:
-  // Attempts to find `key` in the table; if it isn't found, returns a slot that
-  // the value can be inserted into, with the control byte already set to
-  // `key`'s H2.
   template <class K>
-  std::pair<size_t, bool> find_or_prepare_insert(const K& key) {
+  std::pair<iterator, bool> find_or_prepare_insert_soo(const K& key) {
+    if (empty()) {
+      const HashtablezInfoHandle infoz = try_sample_soo();
+      if (infoz.IsSampled()) {
+        resize_with_soo_infoz(infoz);
+      } else {
+        common().set_full_soo();
+        return {soo_iterator(), true};
+      }
+    } else if (PolicyTraits::apply(EqualElement<K>{key, eq_ref()},
+                                   PolicyTraits::element(soo_slot()))) {
+      return {soo_iterator(), false};
+    } else {
+      resize(NextCapacity(SooCapacity()));
+    }
+    const size_t index =
+        PrepareInsertAfterSoo(hash_ref()(key), sizeof(slot_type), common());
+    return {iterator_at(index), true};
+  }
+
+  template <class K>
+  std::pair<iterator, bool> find_or_prepare_insert_non_soo(const K& key) {
+    assert(!is_soo());
     prefetch_heap_block();
     auto hash = hash_ref()(key);
     auto seq = probe(common(), hash);
@@ -3094,65 +3814,92 @@ class raw_hash_set {
         if (Y_ABSL_PREDICT_TRUE(PolicyTraits::apply(
                 EqualElement<K>{key, eq_ref()},
                 PolicyTraits::element(slot_array() + seq.offset(i)))))
-          return {seq.offset(i), false};
+          return {iterator_at(seq.offset(i)), false};
+      }
+      auto mask_empty = g.MaskEmpty();
+      if (Y_ABSL_PREDICT_TRUE(mask_empty)) {
+        size_t target = seq.offset(
+            GetInsertionOffset(mask_empty, capacity(), hash, control()));
+        return {iterator_at(PrepareInsertNonSoo(common(), hash,
+                                                FindInfo{target, seq.index()},
+                                                GetPolicyFunctions())),
+                true};
       }
-      if (Y_ABSL_PREDICT_TRUE(g.MaskEmpty())) break;
       seq.next();
       assert(seq.index() <= capacity() && "full table!");
     }
-    return {prepare_insert(hash), true};
   }
 
-  // Given the hash of a value not currently in the table, finds the next
-  // viable slot index to insert it at.
-  //
-  // REQUIRES: At least one non-full slot available.
-  size_t prepare_insert(size_t hash) Y_ABSL_ATTRIBUTE_NOINLINE {
-    const bool rehash_for_bug_detection =
-        common().should_rehash_for_bug_detection_on_insert();
-    if (rehash_for_bug_detection) {
-      // Move to a different heap allocation in order to detect bugs.
-      const size_t cap = capacity();
-      resize(growth_left() > 0 ? cap : NextCapacity(cap));
-    }
-    auto target = find_first_non_full(common(), hash);
-    if (!rehash_for_bug_detection &&
-        Y_ABSL_PREDICT_FALSE(growth_left() == 0 &&
-                           !IsDeleted(control()[target.offset]))) {
-      size_t old_capacity = capacity();
-      rehash_and_grow_if_necessary();
-      // NOTE: It is safe to use `FindFirstNonFullAfterResize`.
-      // `FindFirstNonFullAfterResize` must be called right after resize.
-      // `rehash_and_grow_if_necessary` may *not* call `resize`
-      // and perform `drop_deletes_without_resize` instead. But this
-      // could happen only on big tables.
-      // For big tables `FindFirstNonFullAfterResize` will always
-      // fallback to normal `find_first_non_full`, so it is safe to use it.
-      target = HashSetResizeHelper::FindFirstNonFullAfterResize(
-          common(), old_capacity, hash);
-    }
-    common().increment_size();
-    set_growth_left(growth_left() - IsEmpty(control()[target.offset]));
-    SetCtrl(common(), target.offset, H2(hash), sizeof(slot_type));
-    common().maybe_increment_generation_on_insert();
-    infoz().RecordInsert(hash, target.probe_length);
-    return target.offset;
+ protected:
+  // Asserts that hash and equal functors provided by the user are consistent,
+  // meaning that `eq(k1, k2)` implies `hash(k1)==hash(k2)`.
+  template <class K>
+  void AssertHashEqConsistent(Y_ABSL_ATTRIBUTE_UNUSED const K& key) {
+#ifndef NDEBUG
+    if (empty()) return;
+
+    const size_t hash_of_arg = hash_ref()(key);
+    const auto assert_consistent = [&](const ctrl_t*, slot_type* slot) {
+      const value_type& element = PolicyTraits::element(slot);
+      const bool is_key_equal =
+          PolicyTraits::apply(EqualElement<K>{key, eq_ref()}, element);
+      if (!is_key_equal) return;
+
+      const size_t hash_of_slot =
+          PolicyTraits::apply(HashElement{hash_ref()}, element);
+      const bool is_hash_equal = hash_of_arg == hash_of_slot;
+      if (!is_hash_equal) {
+        // In this case, we're going to crash. Do a couple of other checks for
+        // idempotence issues. Recalculating hash/eq here is also convenient for
+        // debugging with gdb/lldb.
+        const size_t once_more_hash_arg = hash_ref()(key);
+        assert(hash_of_arg == once_more_hash_arg && "hash is not idempotent.");
+        const size_t once_more_hash_slot =
+            PolicyTraits::apply(HashElement{hash_ref()}, element);
+        assert(hash_of_slot == once_more_hash_slot &&
+               "hash is not idempotent.");
+        const bool once_more_eq =
+            PolicyTraits::apply(EqualElement<K>{key, eq_ref()}, element);
+        assert(is_key_equal == once_more_eq && "equality is not idempotent.");
+      }
+      assert((!is_key_equal || is_hash_equal) &&
+             "eq(k1, k2) must imply that hash(k1) == hash(k2). "
+             "hash/eq functors are inconsistent.");
+    };
+
+    if (is_soo()) {
+      assert_consistent(/*unused*/ nullptr, soo_slot());
+      return;
+    }
+    // We only do validation for small tables so that it's constant time.
+    if (capacity() > 16) return;
+    IterateOverFullSlots(common(), slot_array(), assert_consistent);
+#endif
+  }
+
+  // Attempts to find `key` in the table; if it isn't found, returns an iterator
+  // where the value can be inserted into, with the control byte already set to
+  // `key`'s H2. Returns a bool indicating whether an insertion can take place.
+  template <class K>
+  std::pair<iterator, bool> find_or_prepare_insert(const K& key) {
+    AssertHashEqConsistent(key);
+    if (is_soo()) return find_or_prepare_insert_soo(key);
+    return find_or_prepare_insert_non_soo(key);
   }
 
   // Constructs the value in the space pointed by the iterator. This only works
   // after an unsuccessful find_or_prepare_insert() and before any other
   // modifications happen in the raw_hash_set.
   //
-  // PRECONDITION: i is an index returned from find_or_prepare_insert(k), where
-  // k is the key decomposed from `forward<Args>(args)...`, and the bool
-  // returned by find_or_prepare_insert(k) was true.
+  // PRECONDITION: iter was returned from find_or_prepare_insert(k), where k is
+  // the key decomposed from `forward<Args>(args)...`, and the bool returned by
+  // find_or_prepare_insert(k) was true.
   // POSTCONDITION: *m.iterator_at(i) == value_type(forward<Args>(args)...).
   template <class... Args>
-  void emplace_at(size_t i, Args&&... args) {
-    construct(slot_array() + i, std::forward<Args>(args)...);
+  void emplace_at(iterator iter, Args&&... args) {
+    construct(iter.slot(), std::forward<Args>(args)...);
 
-    assert(PolicyTraits::apply(FindElement{*this}, *iterator_at(i)) ==
-               iterator_at(i) &&
+    assert(PolicyTraits::apply(FindElement{*this}, *iter) == iter &&
            "constructed value does not match the lookup key");
   }
 
@@ -3160,7 +3907,7 @@ class raw_hash_set {
     return {control() + i, slot_array() + i, common().generation_ptr()};
   }
   const_iterator iterator_at(size_t i) const Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
-    return {control() + i, slot_array() + i, common().generation_ptr()};
+    return const_cast<raw_hash_set*>(this)->iterator_at(i);
   }
 
   reference unchecked_deref(iterator it) { return it.unchecked_deref(); }
@@ -3178,13 +3925,25 @@ class raw_hash_set {
   // side-effect.
   //
   // See `CapacityToGrowth()`.
-  size_t growth_left() const { return common().growth_left(); }
-  void set_growth_left(size_t gl) { return common().set_growth_left(gl); }
+  size_t growth_left() const {
+    assert(!is_soo());
+    return common().growth_left();
+  }
+
+  GrowthInfo& growth_info() {
+    assert(!is_soo());
+    return common().growth_info();
+  }
+  GrowthInfo growth_info() const {
+    assert(!is_soo());
+    return common().growth_info();
+  }
 
   // Prefetch the heap-allocated memory region to resolve potential TLB and
   // cache misses. This is intended to overlap with execution of calculating the
   // hash for a key.
   void prefetch_heap_block() const {
+    assert(!is_soo());
 #if Y_ABSL_HAVE_BUILTIN(__builtin_prefetch) || defined(__GNUC__)
     __builtin_prefetch(control(), 0, 1);
 #endif
@@ -3193,11 +3952,31 @@ class raw_hash_set {
   CommonFields& common() { return settings_.template get<0>(); }
   const CommonFields& common() const { return settings_.template get<0>(); }
 
-  ctrl_t* control() const { return common().control(); }
+  ctrl_t* control() const {
+    assert(!is_soo());
+    return common().control();
+  }
   slot_type* slot_array() const {
+    assert(!is_soo());
     return static_cast<slot_type*>(common().slot_array());
   }
-  HashtablezInfoHandle infoz() { return common().infoz(); }
+  slot_type* soo_slot() {
+    assert(is_soo());
+    return static_cast<slot_type*>(common().soo_data());
+  }
+  const slot_type* soo_slot() const {
+    return const_cast<raw_hash_set*>(this)->soo_slot();
+  }
+  iterator soo_iterator() {
+    return {SooControl(), soo_slot(), common().generation_ptr()};
+  }
+  const_iterator soo_iterator() const {
+    return const_cast<raw_hash_set*>(this)->soo_iterator();
+  }
+  HashtablezInfoHandle infoz() {
+    assert(!is_soo());
+    return common().infoz();
+  }
 
   hasher& hash_ref() { return settings_.template get<1>(); }
   const hasher& hash_ref() const { return settings_.template get<1>(); }
@@ -3208,12 +3987,9 @@ class raw_hash_set {
     return settings_.template get<3>();
   }
 
-  // Make type-specific functions for this type's PolicyFunctions struct.
-  static size_t hash_slot_fn(void* set, void* slot) {
-    auto* h = static_cast<raw_hash_set*>(set);
-    return PolicyTraits::apply(
-        HashElement{h->hash_ref()},
-        PolicyTraits::element(static_cast<slot_type*>(slot)));
+  static const void* get_hash_ref_fn(const CommonFields& common) {
+    auto* h = reinterpret_cast<const raw_hash_set*>(&common);
+    return &h->hash_ref();
   }
   static void transfer_slot_fn(void* set, void* dst, void* src) {
     auto* h = static_cast<raw_hash_set*>(set);
@@ -3236,13 +4012,18 @@ class raw_hash_set {
   static const PolicyFunctions& GetPolicyFunctions() {
     static constexpr PolicyFunctions value = {
         sizeof(slot_type),
-        &raw_hash_set::hash_slot_fn,
+        // TODO(b/328722020): try to type erase
+        // for standard layout and alignof(Hash) <= alignof(CommonFields).
+        std::is_empty<hasher>::value ? &GetHashRefForEmptyHasher
+                                     : &raw_hash_set::get_hash_ref_fn,
+        PolicyTraits::template get_hash_slot_fn<hasher>(),
         PolicyTraits::transfer_uses_memcpy()
             ? TransferRelocatable<sizeof(slot_type)>
             : &raw_hash_set::transfer_slot_fn,
         (std::is_same<SlotAlloc, std::allocator<slot_type>>::value
              ? &DeallocateStandard<alignof(slot_type)>
              : &raw_hash_set::dealloc_fn),
+        &raw_hash_set::resize_impl,
     };
     return value;
   }
@@ -3252,22 +4033,78 @@ class raw_hash_set {
   // fields that occur after CommonFields.
   y_absl::container_internal::CompressedTuple<CommonFields, hasher, key_equal,
                                             allocator_type>
-      settings_{CommonFields{}, hasher{}, key_equal{}, allocator_type{}};
+      settings_{CommonFields::CreateDefault<SooEnabled()>(), hasher{},
+                key_equal{}, allocator_type{}};
+};
+
+// Friend access for free functions in raw_hash_set.h.
+struct HashtableFreeFunctionsAccess {
+  template <class Predicate, typename Set>
+  static typename Set::size_type EraseIf(Predicate& pred, Set* c) {
+    if (c->empty()) {
+      return 0;
+    }
+    if (c->is_soo()) {
+      auto it = c->soo_iterator();
+      if (!pred(*it)) {
+        assert(c->size() == 1 && "hash table was modified unexpectedly");
+        return 0;
+      }
+      c->destroy(it.slot());
+      c->common().set_empty_soo();
+      return 1;
+    }
+    Y_ABSL_ATTRIBUTE_UNUSED const size_t original_size_for_assert = c->size();
+    size_t num_deleted = 0;
+    IterateOverFullSlots(
+        c->common(), c->slot_array(), [&](const ctrl_t* ctrl, auto* slot) {
+          if (pred(Set::PolicyTraits::element(slot))) {
+            c->destroy(slot);
+            EraseMetaOnly(c->common(), static_cast<size_t>(ctrl - c->control()),
+                          sizeof(*slot));
+            ++num_deleted;
+          }
+        });
+    // NOTE: IterateOverFullSlots allow removal of the current element, so we
+    // verify the size additionally here.
+    assert(original_size_for_assert - num_deleted == c->size() &&
+           "hash table was modified unexpectedly");
+    return num_deleted;
+  }
+
+  template <class Callback, typename Set>
+  static void ForEach(Callback& cb, Set* c) {
+    if (c->empty()) {
+      return;
+    }
+    if (c->is_soo()) {
+      cb(*c->soo_iterator());
+      return;
+    }
+    using ElementTypeWithConstness = decltype(*c->begin());
+    IterateOverFullSlots(
+        c->common(), c->slot_array(), [&cb](const ctrl_t*, auto* slot) {
+          ElementTypeWithConstness& element = Set::PolicyTraits::element(slot);
+          cb(element);
+        });
+  }
 };
 
 // Erases all elements that satisfy the predicate `pred` from the container `c`.
 template <typename P, typename H, typename E, typename A, typename Predicate>
 typename raw_hash_set<P, H, E, A>::size_type EraseIf(
     Predicate& pred, raw_hash_set<P, H, E, A>* c) {
-  const auto initial_size = c->size();
-  for (auto it = c->begin(), last = c->end(); it != last;) {
-    if (pred(*it)) {
-      c->erase(it++);
-    } else {
-      ++it;
-    }
-  }
-  return initial_size - c->size();
+  return HashtableFreeFunctionsAccess::EraseIf(pred, c);
+}
+
+// Calls `cb` for all elements in the container `c`.
+template <typename P, typename H, typename E, typename A, typename Callback>
+void ForEach(Callback& cb, raw_hash_set<P, H, E, A>* c) {
+  return HashtableFreeFunctionsAccess::ForEach(cb, c);
+}
+template <typename P, typename H, typename E, typename A, typename Callback>
+void ForEach(Callback& cb, const raw_hash_set<P, H, E, A>* c) {
+  return HashtableFreeFunctionsAccess::ForEach(cb, c);
 }
 
 namespace hashtable_debug_internal {
@@ -3278,6 +4115,7 @@ struct HashtableDebugAccess<Set, y_absl::void_t<typename Set::raw_hash_set>> {
 
   static size_t GetNumProbes(const Set& set,
                              const typename Set::key_type& key) {
+    if (set.is_soo()) return 0;
     size_t num_probes = 0;
     size_t hash = set.hash_ref()(key);
     auto seq = probe(set.common(), hash);
@@ -3301,7 +4139,8 @@ struct HashtableDebugAccess<Set, y_absl::void_t<typename Set::raw_hash_set>> {
   static size_t AllocatedByteSize(const Set& c) {
     size_t capacity = c.capacity();
     if (capacity == 0) return 0;
-    size_t m = c.common().alloc_size(sizeof(Slot), alignof(Slot));
+    size_t m =
+        c.is_soo() ? 0 : c.common().alloc_size(sizeof(Slot), alignof(Slot));
 
     size_t per_slot = Traits::space_used(static_cast<const Slot*>(nullptr));
     if (per_slot != ~size_t{}) {
@@ -3321,5 +4160,7 @@ Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
 
 #undef Y_ABSL_SWISSTABLE_ENABLE_GENERATIONS
+#undef Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED
+#undef Y_ABSL_SWISSTABLE_IGNORE_UNINITIALIZED_RETURN
 
 #endif  // Y_ABSL_CONTAINER_INTERNAL_RAW_HASH_SET_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc32_x86_arm_combined_simd.h b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc32_x86_arm_combined_simd.h
index 0e53b0f573..c1bbdf498f 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc32_x86_arm_combined_simd.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc32_x86_arm_combined_simd.h
@@ -33,14 +33,15 @@
 #include <x86intrin.h>
 #define Y_ABSL_CRC_INTERNAL_HAVE_X86_SIMD
 
-#elif defined(_MSC_VER) && !defined(__clang__) && defined(__AVX__)
+#elif defined(_MSC_VER) && !defined(__clang__) && defined(__AVX__) && \
+    defined(_M_AMD64)
 
 // MSVC AVX (/arch:AVX) implies SSE 4.2 and PCLMULQDQ.
 #include <intrin.h>
 #define Y_ABSL_CRC_INTERNAL_HAVE_X86_SIMD
 
-#elif defined(__aarch64__) && defined(__LITTLE_ENDIAN__) && \
-    defined(__ARM_FEATURE_CRC32) && defined(Y_ABSL_INTERNAL_HAVE_ARM_NEON) &&  \
+#elif defined(__aarch64__) && defined(__LITTLE_ENDIAN__) &&                 \
+    defined(__ARM_FEATURE_CRC32) && defined(Y_ABSL_INTERNAL_HAVE_ARM_NEON) && \
     defined(__ARM_FEATURE_CRYPTO)
 
 #include <arm_acle.h>
@@ -101,10 +102,11 @@ V128 V128_Xor(const V128 l, const V128 r);
 // Produces an AND operation of |l| and |r|.
 V128 V128_And(const V128 l, const V128 r);
 
-// Sets two 64 bit integers to one 128 bit vector. The order is reverse.
+// Sets the lower half of a 128 bit register to the given 64-bit value and
+// zeroes the upper half.
 // dst[63:0] := |r|
-// dst[127:64] := |l|
-V128 V128_From2x64(const uint64_t l, const uint64_t r);
+// dst[127:64] := |0|
+V128 V128_From64WithZeroFill(const uint64_t r);
 
 // Shift |l| right by |imm| bytes while shifting in zeros.
 template <int imm>
@@ -121,8 +123,8 @@ uint64_t V128_Extract64(const V128 l);
 // Extracts the low 64 bits from V128.
 int64_t V128_Low64(const V128 l);
 
-// Left-shifts packed 64-bit integers in l by r.
-V128 V128_ShiftLeft64(const V128 l, const V128 r);
+// Add packed 64-bit integers in |l| and |r|.
+V128 V128_Add64(const V128 l, const V128 r);
 
 #endif
 
@@ -170,8 +172,8 @@ inline V128 V128_Xor(const V128 l, const V128 r) { return _mm_xor_si128(l, r); }
 
 inline V128 V128_And(const V128 l, const V128 r) { return _mm_and_si128(l, r); }
 
-inline V128 V128_From2x64(const uint64_t l, const uint64_t r) {
-  return _mm_set_epi64x(static_cast<int64_t>(l), static_cast<int64_t>(r));
+inline V128 V128_From64WithZeroFill(const uint64_t r) {
+  return _mm_set_epi64x(static_cast<int64_t>(0), static_cast<int64_t>(r));
 }
 
 template <int imm>
@@ -191,8 +193,8 @@ inline uint64_t V128_Extract64(const V128 l) {
 
 inline int64_t V128_Low64(const V128 l) { return _mm_cvtsi128_si64(l); }
 
-inline V128 V128_ShiftLeft64(const V128 l, const V128 r) {
-  return _mm_sll_epi64(l, r);
+inline V128 V128_Add64(const V128 l, const V128 r) {
+  return _mm_add_epi64(l, r);
 }
 
 #elif defined(Y_ABSL_CRC_INTERNAL_HAVE_ARM_SIMD)
@@ -261,10 +263,12 @@ inline V128 V128_Xor(const V128 l, const V128 r) { return veorq_u64(l, r); }
 
 inline V128 V128_And(const V128 l, const V128 r) { return vandq_u64(l, r); }
 
-inline V128 V128_From2x64(const uint64_t l, const uint64_t r) {
-  return vcombine_u64(vcreate_u64(r), vcreate_u64(l));
+inline V128 V128_From64WithZeroFill(const uint64_t r){
+  constexpr uint64x2_t kZero = {0, 0};
+  return vsetq_lane_u64(r, kZero, 0);
 }
 
+
 template <int imm>
 inline V128 V128_ShiftRight(const V128 l) {
   return vreinterpretq_u64_s8(
@@ -285,9 +289,7 @@ inline int64_t V128_Low64(const V128 l) {
   return vgetq_lane_s64(vreinterpretq_s64_u64(l), 0);
 }
 
-inline V128 V128_ShiftLeft64(const V128 l, const V128 r) {
-  return vshlq_u64(l, vreinterpretq_s64_u64(r));
-}
+inline V128 V128_Add64(const V128 l, const V128 r) { return vaddq_u64(l, r); }
 
 #endif
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_cord_state.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_cord_state.cc
index 695f2db14a..71a4088dec 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_cord_state.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_cord_state.cc
@@ -17,6 +17,7 @@
 #include <cassert>
 
 #include "y_absl/base/config.h"
+#include "y_absl/base/no_destructor.h"
 #include "y_absl/numeric/bits.h"
 
 namespace y_absl {
@@ -24,14 +25,14 @@ Y_ABSL_NAMESPACE_BEGIN
 namespace crc_internal {
 
 CrcCordState::RefcountedRep* CrcCordState::RefSharedEmptyRep() {
-  static CrcCordState::RefcountedRep* empty = new CrcCordState::RefcountedRep;
+  static y_absl::NoDestructor<CrcCordState::RefcountedRep> empty;
 
   assert(empty->count.load(std::memory_order_relaxed) >= 1);
   assert(empty->rep.removed_prefix.length == 0);
   assert(empty->rep.prefix_crc.empty());
 
-  Ref(empty);
-  return empty;
+  Ref(empty.get());
+  return empty.get();
 }
 
 CrcCordState::CrcCordState() : refcounted_rep_(new RefcountedRep) {}
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_fallback.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_fallback.cc
index cf03a5e10c..5b0cac2542 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_fallback.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_fallback.cc
@@ -12,12 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <cstdint>
+#include <cstring>
 #include <memory>
 
 #include "y_absl/base/config.h"
 #include "y_absl/crc/crc32c.h"
 #include "y_absl/crc/internal/crc_memcpy.h"
+#include "y_absl/strings/string_view.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_x86_arm_combined.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_x86_arm_combined.cc
index e88e235cd4..ab65d3f8a0 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_x86_arm_combined.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_memcpy_x86_arm_combined.cc
@@ -52,6 +52,7 @@
 #include <cstring>
 #include <memory>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/optimization.h"
 #include "y_absl/base/prefetch.h"
@@ -88,9 +89,11 @@ inline crc32c_t ShortCrcCopy(char* dst, const char* src, std::size_t length,
 constexpr size_t kIntLoadsPerVec = sizeof(V128) / sizeof(uint64_t);
 
 // Common function for copying the tails of multiple large regions.
+// Disable ubsan for benign unaligned access. See b/254108538.
 template <size_t vec_regions, size_t int_regions>
-inline void LargeTailCopy(crc32c_t* crcs, char** dst, const char** src,
-                          size_t region_size, size_t copy_rounds) {
+Y_ABSL_ATTRIBUTE_NO_SANITIZE_UNDEFINED inline void LargeTailCopy(
+    crc32c_t* crcs, char** dst, const char** src, size_t region_size,
+    size_t copy_rounds) {
   std::array<V128, vec_regions> data;
   std::array<uint64_t, kIntLoadsPerVec * int_regions> int_data;
 
@@ -127,8 +130,8 @@ inline void LargeTailCopy(crc32c_t* crcs, char** dst, const char** src,
         size_t data_index = i * kIntLoadsPerVec + j;
 
         int_data[data_index] = *(usrc + j);
-        crcs[region] = crc32c_t{static_cast<uint32_t>(CRC32_u64(
-            static_cast<uint32_t>(crcs[region]), int_data[data_index]))};
+        crcs[region] = crc32c_t{CRC32_u64(static_cast<uint32_t>(crcs[region]),
+                                          int_data[data_index])};
 
         *(udst + j) = int_data[data_index];
       }
@@ -155,8 +158,10 @@ class AcceleratedCrcMemcpyEngine : public CrcMemcpyEngine {
                    std::size_t length, crc32c_t initial_crc) const override;
 };
 
+// Disable ubsan for benign unaligned access. See b/254108538.
 template <size_t vec_regions, size_t int_regions>
-crc32c_t AcceleratedCrcMemcpyEngine<vec_regions, int_regions>::Compute(
+Y_ABSL_ATTRIBUTE_NO_SANITIZE_UNDEFINED crc32c_t
+AcceleratedCrcMemcpyEngine<vec_regions, int_regions>::Compute(
     void* __restrict dst, const void* __restrict src, std::size_t length,
     crc32c_t initial_crc) const {
   constexpr std::size_t kRegions = vec_regions + int_regions;
@@ -196,7 +201,6 @@ crc32c_t AcceleratedCrcMemcpyEngine<vec_regions, int_regions>::Compute(
 
   // Start work on the CRC: undo the XOR from the previous calculation or set up
   // the initial value of the CRC.
-  // initial_crc ^= kCrcDataXor;
   initial_crc = crc32c_t{static_cast<uint32_t>(initial_crc) ^ kCrcDataXor};
 
   // Do an initial alignment copy, so we can use aligned store instructions to
@@ -295,8 +299,8 @@ crc32c_t AcceleratedCrcMemcpyEngine<vec_regions, int_regions>::Compute(
 
           // Load and CRC the data.
           int_data[data_index] = *(usrc + i * kIntLoadsPerVec + k);
-          crcs[region] = crc32c_t{static_cast<uint32_t>(CRC32_u64(
-              static_cast<uint32_t>(crcs[region]), int_data[data_index]))};
+          crcs[region] = crc32c_t{CRC32_u64(static_cast<uint32_t>(crcs[region]),
+                                            int_data[data_index])};
 
           // Store the data.
           *(udst + i * kIntLoadsPerVec + k) = int_data[data_index];
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_non_temporal_memcpy.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_non_temporal_memcpy.cc
index e73e6487cf..78dec49f28 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_non_temporal_memcpy.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_non_temporal_memcpy.cc
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <cstdint>
+#include <cstddef>
 
 #include "y_absl/base/config.h"
 #include "y_absl/crc/crc32c.h"
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_x86_arm_combined.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_x86_arm_combined.cc
index d72151a5f1..88a953efad 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_x86_arm_combined.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/crc_x86_arm_combined.cc
@@ -101,13 +101,17 @@ constexpr size_t kMediumCutoff = 2048;
 namespace {
 
 uint32_t multiply(uint32_t a, uint32_t b) {
-  V128 shifts = V128_From2x64(0, 1);
-  V128 power = V128_From2x64(0, a);
-  V128 crc = V128_From2x64(0, b);
+  V128 power = V128_From64WithZeroFill(a);
+  V128 crc = V128_From64WithZeroFill(b);
   V128 res = V128_PMulLow(power, crc);
 
-  // Combine crc values
-  res = V128_ShiftLeft64(res, shifts);
+  // Combine crc values.
+  //
+  // Adding res to itself is equivalent to multiplying by 2,
+  // or shifting left by 1. Addition is used as not all compilers
+  // are able to generate optimal code without this hint.
+  // https://godbolt.org/z/rr3fMnf39
+  res = V128_Add64(res, res);
   return static_cast<uint32_t>(V128_Extract32<1>(res)) ^
          CRC32_u32(0, static_cast<uint32_t>(V128_Low64(res)));
 }
@@ -444,11 +448,11 @@ class CRC32AcceleratedX86ARMCombinedMultipleStreams
 
         V128 magic = *(reinterpret_cast<const V128*>(kClmulConstants) + bs - 1);
 
-        V128 tmp = V128_From2x64(0, l64);
+        V128 tmp = V128_From64WithZeroFill(l64);
 
         V128 res1 = V128_PMulLow(tmp, magic);
 
-        tmp = V128_From2x64(0, l641);
+        tmp = V128_From64WithZeroFill(l641);
 
         V128 res2 = V128_PMul10(tmp, magic);
         V128 x = V128_Xor(res1, res2);
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/non_temporal_memcpy.h b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/non_temporal_memcpy.h
index fce0007046..80f3671424 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/non_temporal_memcpy.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/crc/internal/non_temporal_memcpy.h
@@ -19,19 +19,8 @@
 #include <intrin.h>
 #endif
 
-#ifdef __SSE__
-#include <xmmintrin.h>
-#endif
-
-#ifdef __SSE2__
-#include <emmintrin.h>
-#endif
-
-#ifdef __SSE3__
-#include <pmmintrin.h>
-#endif
-
-#ifdef __AVX__
+#if defined(__SSE__) || defined(__AVX__)
+// Pulls in both SSE and AVX intrinsics.
 #include <immintrin.h>
 #endif
 
@@ -44,6 +33,7 @@
 #include <cstdint>
 #include <cstring>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/optimization.h"
 
@@ -57,7 +47,9 @@ namespace crc_internal {
 // memcpy can save 1 DRAM load of the destination cacheline.
 constexpr size_t kCacheLineSize = Y_ABSL_CACHELINE_SIZE;
 
-// If the objects overlap, the behavior is undefined.
+// If the objects overlap, the behavior is undefined. Uses regular memcpy
+// instead of non-temporal memcpy if the required CPU intrinsics are unavailable
+// at compile time.
 inline void *non_temporal_store_memcpy(void *__restrict dst,
                                        const void *__restrict src, size_t len) {
 #if defined(__SSE3__) || defined(__aarch64__) || \
@@ -119,10 +111,20 @@ inline void *non_temporal_store_memcpy(void *__restrict dst,
 #endif  // __SSE3__ || __aarch64__ || (_MSC_VER && __AVX__)
 }
 
+// If the objects overlap, the behavior is undefined. Uses regular memcpy
+// instead of non-temporal memcpy if the required CPU intrinsics are unavailable
+// at compile time.
+#if Y_ABSL_HAVE_CPP_ATTRIBUTE(gnu::target) && \
+    (defined(__x86_64__) || defined(__i386__))
+[[gnu::target("avx")]]
+#endif
 inline void *non_temporal_store_memcpy_avx(void *__restrict dst,
                                            const void *__restrict src,
                                            size_t len) {
-#ifdef __AVX__
+  // This function requires AVX. For clang and gcc we compile it with AVX even
+  // if the translation unit isn't built with AVX support. This works because we
+  // only select this implementation at runtime if the CPU supports AVX.
+#if defined(__SSE3__) || (defined(_MSC_VER) && defined(__AVX__))
   uint8_t *d = reinterpret_cast<uint8_t *>(dst);
   const uint8_t *s = reinterpret_cast<const uint8_t *>(src);
 
@@ -168,9 +170,8 @@ inline void *non_temporal_store_memcpy_avx(void *__restrict dst,
   }
   return dst;
 #else
-  // Fallback to regular memcpy when AVX is not available.
   return memcpy(dst, src, len);
-#endif  // __AVX__
+#endif  // __SSE3__ || (_MSC_VER && __AVX__)
 }
 
 }  // namespace crc_internal
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/failure_signal_handler.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/failure_signal_handler.h
index 03ce76be42..0766fbeee9 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/failure_signal_handler.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/failure_signal_handler.h
@@ -33,7 +33,7 @@
 // }
 //
 // Any program that raises a fatal signal (such as `SIGSEGV`, `SIGILL`,
-// `SIGFPE`, `SIGABRT`, `SIGTERM`, `SIGBUG`, and `SIGTRAP`) will call the
+// `SIGFPE`, `SIGABRT`, `SIGTERM`, `SIGBUS`, and `SIGTRAP`) will call the
 // installed failure signal handler and provide debugging information to stderr.
 //
 // Note that you should *not* install the Abseil failure signal handler more
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/bounded_utf8_length_sequence.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/bounded_utf8_length_sequence.h
new file mode 100644
index 0000000000..df2804299b
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/bounded_utf8_length_sequence.h
@@ -0,0 +1,126 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef Y_ABSL_DEBUGGING_INTERNAL_BOUNDED_UTF8_LENGTH_SEQUENCE_H_
+#define Y_ABSL_DEBUGGING_INTERNAL_BOUNDED_UTF8_LENGTH_SEQUENCE_H_
+
+#include <cstdint>
+
+#include "y_absl/base/config.h"
+#include "y_absl/numeric/bits.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// A sequence of up to max_elements integers between 1 and 4 inclusive, whose
+// insertion operation computes the sum of all the elements before the insertion
+// point.  This is useful in decoding Punycode, where one needs to know where in
+// a UTF-8 byte stream the n-th code point begins.
+//
+// BoundedUtf8LengthSequence is async-signal-safe and suitable for use in
+// symbolizing stack traces in a signal handler, provided max_elements is not
+// improvidently large.  For inputs of lengths accepted by the Rust demangler,
+// up to a couple hundred code points, InsertAndReturnSumOfPredecessors should
+// run in a few dozen clock cycles, on par with the other arithmetic required
+// for Punycode decoding.
+template <uint32_t max_elements>
+class BoundedUtf8LengthSequence {
+ public:
+  // Constructs an empty sequence.
+  BoundedUtf8LengthSequence() = default;
+
+  // Inserts `utf_length` at position `index`, shifting any existing elements at
+  // or beyond `index` one position to the right.  If the sequence is already
+  // full, the rightmost element is discarded.
+  //
+  // Returns the sum of the elements at positions 0 to `index - 1` inclusive.
+  // If `index` is greater than the number of elements already inserted, the
+  // excess positions in the range count 1 apiece.
+  //
+  // REQUIRES: index < max_elements and 1 <= utf8_length <= 4.
+  uint32_t InsertAndReturnSumOfPredecessors(
+      uint32_t index, uint32_t utf8_length) {
+    // The caller shouldn't pass out-of-bounds inputs, but if it does happen,
+    // clamp the values and try to continue.  If we're being called from a
+    // signal handler, the last thing we want to do is crash.  Emitting
+    // malformed UTF-8 is a lesser evil.
+    if (index >= max_elements) index = max_elements - 1;
+    if (utf8_length == 0 || utf8_length > 4) utf8_length = 1;
+
+    const uint32_t word_index = index/32;
+    const uint32_t bit_index = 2 * (index % 32);
+    const uint64_t ones_bit = uint64_t{1} << bit_index;
+
+    // Compute the sum of predecessors.
+    //   - Each value from 1 to 4 is represented by a bit field with value from
+    //     0 to 3, so the desired sum is index plus the sum of the
+    //     representations actually stored.
+    //   - For each bit field, a set low bit should contribute 1 to the sum, and
+    //     a set high bit should contribute 2.
+    //   - Another way to say the same thing is that each set bit contributes 1,
+    //     and each set high bit contributes an additional 1.
+    //   - So the sum we want is index + popcount(everything) + popcount(bits in
+    //     odd positions).
+    const uint64_t odd_bits_mask = 0xaaaaaaaaaaaaaaaa;
+    const uint64_t lower_seminibbles_mask = ones_bit - 1;
+    const uint64_t higher_seminibbles_mask = ~lower_seminibbles_mask;
+    const uint64_t same_word_bits_below_insertion =
+        rep_[word_index] & lower_seminibbles_mask;
+    int full_popcount = y_absl::popcount(same_word_bits_below_insertion);
+    int odd_popcount =
+        y_absl::popcount(same_word_bits_below_insertion & odd_bits_mask);
+    for (uint32_t j = word_index; j > 0; --j) {
+      const uint64_t word_below_insertion = rep_[j - 1];
+      full_popcount += y_absl::popcount(word_below_insertion);
+      odd_popcount += y_absl::popcount(word_below_insertion & odd_bits_mask);
+    }
+    const uint32_t sum_of_predecessors =
+        index + static_cast<uint32_t>(full_popcount + odd_popcount);
+
+    // Now insert utf8_length's representation, shifting successors up one
+    // place.
+    for (uint32_t j = max_elements/32 - 1; j > word_index; --j) {
+      rep_[j] = (rep_[j] << 2) | (rep_[j - 1] >> 62);
+    }
+    rep_[word_index] =
+        (rep_[word_index] & lower_seminibbles_mask) |
+        (uint64_t{utf8_length - 1} << bit_index) |
+        ((rep_[word_index] & higher_seminibbles_mask) << 2);
+
+    return sum_of_predecessors;
+  }
+
+ private:
+  // If the (32 * i + j)-th element of the represented sequence has the value k
+  // (0 <= j < 32, 1 <= k <= 4), then bits 2 * j and 2 * j + 1 of rep_[i]
+  // contain the seminibble (k - 1).
+  //
+  // In particular, the zero-initialization of rep_ makes positions not holding
+  // any inserted element count as 1 in InsertAndReturnSumOfPredecessors.
+  //
+  // Example: rep_ = {0xb1, ... the rest zeroes ...} represents the sequence
+  // (2, 1, 4, 3, ... the rest 1's ...).  Constructing the sequence of Unicode
+  // code points "Àa🂻中" = {U+00C0, U+0061, U+1F0BB, U+4E2D} (among many
+  // other examples) would yield this value of rep_.
+  static_assert(max_elements > 0 && max_elements % 32 == 0,
+                "max_elements must be a positive multiple of 32");
+  uint64_t rep_[max_elements/32] = {};
+};
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_DEBUGGING_INTERNAL_BOUNDED_UTF8_LENGTH_SEQUENCE_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/decode_rust_punycode.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/decode_rust_punycode.cc
new file mode 100644
index 0000000000..bb9fe3cb0e
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/decode_rust_punycode.cc
@@ -0,0 +1,258 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "y_absl/debugging/internal/decode_rust_punycode.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+
+#include "y_absl/base/config.h"
+#include "y_absl/base/nullability.h"
+#include "y_absl/debugging/internal/bounded_utf8_length_sequence.h"
+#include "y_absl/debugging/internal/utf8_for_code_point.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+namespace {
+
+// Decoding Punycode requires repeated random-access insertion into a stream of
+// variable-length UTF-8 code-point encodings.  We need this to be tolerably
+// fast (no N^2 slowdown for unfortunate inputs), and we can't allocate any data
+// structures on the heap (async-signal-safety).
+//
+// It is pragmatic to impose a moderately low limit on the identifier length and
+// bail out if we ever hit it.  Then BoundedUtf8LengthSequence efficiently
+// determines where to insert the next code point, and memmove efficiently makes
+// room for it.
+//
+// The chosen limit is a round number several times larger than identifiers
+// expected in practice, yet still small enough that a memmove of this many
+// UTF-8 characters is not much more expensive than the division and modulus
+// operations that Punycode decoding requires.
+constexpr uint32_t kMaxChars = 256;
+
+// Constants from RFC 3492 section 5.
+constexpr uint32_t kBase = 36, kTMin = 1, kTMax = 26, kSkew = 38, kDamp = 700;
+
+constexpr uint32_t kMaxCodePoint = 0x10ffff;
+
+// Overflow threshold in DecodeRustPunycode's inner loop; see comments there.
+constexpr uint32_t kMaxI = 1 << 30;
+
+// If punycode_begin .. punycode_end begins with a prefix matching the regular
+// expression [0-9a-zA-Z_]+_, removes that prefix, copies all but the final
+// underscore into out_begin .. out_end, sets num_ascii_chars to the number of
+// bytes copied, and returns true.  (A prefix of this sort represents the
+// nonempty subsequence of ASCII characters in the corresponding plaintext.)
+//
+// If punycode_begin .. punycode_end does not contain an underscore, sets
+// num_ascii_chars to zero and returns true.  (The encoding of a plaintext
+// without any ASCII characters does not carry such a prefix.)
+//
+// Returns false and zeroes num_ascii_chars on failure (either parse error or
+// not enough space in the output buffer).
+bool ConsumeOptionalAsciiPrefix(const char*& punycode_begin,
+                                const char* const punycode_end,
+                                char* const out_begin,
+                                char* const out_end,
+                                uint32_t& num_ascii_chars) {
+  num_ascii_chars = 0;
+
+  // Remember the last underscore if any.  Also use the same string scan to
+  // reject any ASCII bytes that do not belong in an identifier, including NUL,
+  // as well as non-ASCII bytes, which should have been delta-encoded instead.
+  int last_underscore = -1;
+  for (int i = 0; i < punycode_end - punycode_begin; ++i) {
+    const char c = punycode_begin[i];
+    if (c == '_') {
+      last_underscore = i;
+      continue;
+    }
+    // We write out the meaning of y_absl::ascii_isalnum rather than call that
+    // function because its documentation does not promise it will remain
+    // async-signal-safe under future development.
+    if ('a' <= c && c <= 'z') continue;
+    if ('A' <= c && c <= 'Z') continue;
+    if ('0' <= c && c <= '9') continue;
+    return false;
+  }
+
+  // If there was no underscore, that means there were no ASCII characters in
+  // the plaintext, so there is no prefix to consume.  Our work is done.
+  if (last_underscore < 0) return true;
+
+  // Otherwise there will be an underscore delimiter somewhere.  It can't be
+  // initial because then there would be no ASCII characters to its left, and no
+  // delimiter would have been added in that case.
+  if (last_underscore == 0) return false;
+
+  // Any other position is reasonable.  Make sure there's room in the buffer.
+  if (last_underscore + 1 > out_end - out_begin) return false;
+
+  // Consume and write out the ASCII characters.
+  num_ascii_chars = static_cast<uint32_t>(last_underscore);
+  std::memcpy(out_begin, punycode_begin, num_ascii_chars);
+  out_begin[num_ascii_chars] = '\0';
+  punycode_begin += num_ascii_chars + 1;
+  return true;
+}
+
+// Returns the value of `c` as a base-36 digit according to RFC 3492 section 5,
+// or -1 if `c` is not such a digit.
+int DigitValue(char c) {
+  if ('0' <= c && c <= '9') return c - '0' + 26;
+  if ('a' <= c && c <= 'z') return c - 'a';
+  if ('A' <= c && c <= 'Z') return c - 'A';
+  return -1;
+}
+
+// Consumes the next delta encoding from punycode_begin .. punycode_end,
+// updating i accordingly.  Returns true on success.  Returns false on parse
+// failure or arithmetic overflow.
+bool ScanNextDelta(const char*& punycode_begin, const char* const punycode_end,
+                   uint32_t bias, uint32_t& i) {
+  uint64_t w = 1;  // 64 bits to prevent overflow in w *= kBase - t
+
+  // "for k = base to infinity in steps of base do begin ... end" in RFC 3492
+  // section 6.2.  Each loop iteration scans one digit of the delta.
+  for (uint32_t k = kBase; punycode_begin != punycode_end; k += kBase) {
+    const int digit_value = DigitValue(*punycode_begin++);
+    if (digit_value < 0) return false;
+
+    // Compute this in 64-bit arithmetic so we can check for overflow afterward.
+    const uint64_t new_i = i + static_cast<uint64_t>(digit_value) * w;
+
+    // Valid deltas are bounded by (#chars already emitted) * kMaxCodePoint, but
+    // invalid input could encode an arbitrarily large delta.  Nip that in the
+    // bud here.
+    static_assert(
+        kMaxI >= kMaxChars * kMaxCodePoint,
+        "kMaxI is too small to prevent spurious failures on good input");
+    if (new_i > kMaxI) return false;
+
+    static_assert(
+        kMaxI < (uint64_t{1} << 32),
+        "Make kMaxI smaller or i 64 bits wide to prevent silent wraparound");
+    i = static_cast<uint32_t>(new_i);
+
+    // Compute the threshold that determines whether this is the last digit and
+    // (if not) what the next digit's place value will be.  This logic from RFC
+    // 3492 section 6.2 is explained in section 3.3.
+    uint32_t t;
+    if (k <= bias + kTMin) {
+      t = kTMin;
+    } else if (k >= bias + kTMax) {
+      t = kTMax;
+    } else {
+      t = k - bias;
+    }
+    if (static_cast<uint32_t>(digit_value) < t) return true;
+
+    // If this gets too large, the range check on new_i in the next iteration
+    // will catch it.  We know this multiplication will not overwrap because w
+    // is 64 bits wide.
+    w *= kBase - t;
+  }
+  return false;
+}
+
+}  // namespace
+
+y_absl::Nullable<char*> DecodeRustPunycode(DecodeRustPunycodeOptions options) {
+  const char* punycode_begin = options.punycode_begin;
+  const char* const punycode_end = options.punycode_end;
+  char* const out_begin = options.out_begin;
+  char* const out_end = options.out_end;
+
+  // Write a NUL terminator first.  Later memcpy calls will keep bumping it
+  // along to its new right place.
+  const size_t out_size = static_cast<size_t>(out_end - out_begin);
+  if (out_size == 0) return nullptr;
+  *out_begin = '\0';
+
+  // RFC 3492 section 6.2 begins here.  We retain the names of integer variables
+  // appearing in that text.
+  uint32_t n = 128, i = 0, bias = 72, num_chars = 0;
+
+  // If there are any ASCII characters, consume them and their trailing
+  // underscore delimiter.
+  if (!ConsumeOptionalAsciiPrefix(punycode_begin, punycode_end,
+                                  out_begin, out_end, num_chars)) {
+    return nullptr;
+  }
+  uint32_t total_utf8_bytes = num_chars;
+
+  BoundedUtf8LengthSequence<kMaxChars> utf8_lengths;
+
+  // "while the input is not exhausted do begin ... end"
+  while (punycode_begin != punycode_end) {
+    if (num_chars >= kMaxChars) return nullptr;
+
+    const uint32_t old_i = i;
+
+    if (!ScanNextDelta(punycode_begin, punycode_end, bias, i)) return nullptr;
+
+    // Update bias as in RFC 3492 section 6.1.  (We have inlined adapt.)
+    uint32_t delta = i - old_i;
+    delta /= (old_i == 0 ? kDamp : 2);
+    delta += delta/(num_chars + 1);
+    bias = 0;
+    while (delta > ((kBase - kTMin) * kTMax)/2) {
+      delta /= kBase - kTMin;
+      bias += kBase;
+    }
+    bias += ((kBase - kTMin + 1) * delta)/(delta + kSkew);
+
+    // Back in section 6.2, compute the new code point and insertion index.
+    static_assert(
+        kMaxI + kMaxCodePoint < (uint64_t{1} << 32),
+        "Make kMaxI smaller or n 64 bits wide to prevent silent wraparound");
+    n += i/(num_chars + 1);
+    i %= num_chars + 1;
+
+    // To actually insert, we need to convert the code point n to UTF-8 and the
+    // character index i to an index into the byte stream emitted so far.  First
+    // prepare the UTF-8 encoding for n, rejecting surrogates, overlarge values,
+    // and anything that won't fit into the remaining output storage.
+    Utf8ForCodePoint utf8_for_code_point(n);
+    if (!utf8_for_code_point.ok()) return nullptr;
+    if (total_utf8_bytes + utf8_for_code_point.length + 1 > out_size) {
+      return nullptr;
+    }
+
+    // Now insert the new character into both our length map and the output.
+    uint32_t n_index =
+        utf8_lengths.InsertAndReturnSumOfPredecessors(
+            i, utf8_for_code_point.length);
+    std::memmove(
+        out_begin + n_index + utf8_for_code_point.length, out_begin + n_index,
+        total_utf8_bytes + 1 - n_index);
+    std::memcpy(out_begin + n_index, utf8_for_code_point.bytes,
+                utf8_for_code_point.length);
+    total_utf8_bytes += utf8_for_code_point.length;
+    ++num_chars;
+
+    // Finally, advance to the next state before continuing.
+    ++i;
+  }
+
+  return out_begin + total_utf8_bytes;
+}
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/decode_rust_punycode.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/decode_rust_punycode.h
new file mode 100644
index 0000000000..b232b4c12f
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/decode_rust_punycode.h
@@ -0,0 +1,55 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef Y_ABSL_DEBUGGING_INTERNAL_DECODE_RUST_PUNYCODE_H_
+#define Y_ABSL_DEBUGGING_INTERNAL_DECODE_RUST_PUNYCODE_H_
+
+#include "y_absl/base/config.h"
+#include "y_absl/base/nullability.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+struct DecodeRustPunycodeOptions {
+  const char* punycode_begin;
+  const char* punycode_end;
+  char* out_begin;
+  char* out_end;
+};
+
+// Given Rust Punycode in `punycode_begin .. punycode_end`, writes the
+// corresponding UTF-8 plaintext into `out_begin .. out_end`, followed by a NUL
+// character, and returns a pointer to that final NUL on success.  On failure
+// returns a null pointer, and the contents of `out_begin .. out_end` are
+// unspecified.
+//
+// Failure occurs in precisely these cases:
+//   - Any input byte does not match [0-9a-zA-Z_].
+//   - The first input byte is an underscore, but no other underscore appears in
+//     the input.
+//   - The delta sequence does not represent a valid sequence of code-point
+//     insertions.
+//   - The plaintext would contain more than 256 code points.
+//
+// DecodeRustPunycode is async-signal-safe with bounded runtime and a small
+// stack footprint, making it suitable for use in demangling Rust symbol names
+// from a signal handler.
+y_absl::Nullable<char*> DecodeRustPunycode(DecodeRustPunycodeOptions options);
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_DEBUGGING_INTERNAL_DECODE_RUST_PUNYCODE_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.cc
index f79c798eef..22848f9861 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.cc
@@ -14,18 +14,19 @@
 
 // For reference check out:
 // https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling
-//
-// Note that we only have partial C++11 support yet.
 
 #include "y_absl/debugging/internal/demangle.h"
 
+#include <cstddef>
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
+#include <cstring>
 #include <limits>
 #include <util/generic/string.h>
 
 #include "y_absl/base/config.h"
+#include "y_absl/debugging/internal/demangle_rust.h"
 
 #if Y_ABSL_INTERNAL_HAS_CXA_DEMANGLE
 #include <cxxabi.h>
@@ -44,14 +45,16 @@ typedef struct {
 
 // List of operators from Itanium C++ ABI.
 static const AbbrevPair kOperatorList[] = {
-    // New has special syntax (not currently supported).
+    // New has special syntax.
     {"nw", "new", 0},
     {"na", "new[]", 0},
 
-    // Works except that the 'gs' prefix is not supported.
+    // Special-cased elsewhere to support the optional gs prefix.
     {"dl", "delete", 1},
     {"da", "delete[]", 1},
 
+    {"aw", "co_await", 1},
+
     {"ps", "+", 1},  // "positive"
     {"ng", "-", 1},  // "negative"
     {"ad", "&", 1},  // "address-of"
@@ -79,6 +82,7 @@ static const AbbrevPair kOperatorList[] = {
     {"rs", ">>", 2},
     {"lS", "<<=", 2},
     {"rS", ">>=", 2},
+    {"ss", "<=>", 2},
     {"eq", "==", 2},
     {"ne", "!=", 2},
     {"lt", "<", 2},
@@ -98,6 +102,7 @@ static const AbbrevPair kOperatorList[] = {
     {"qu", "?", 3},
     {"st", "sizeof", 0},  // Special syntax
     {"sz", "sizeof", 1},  // Not a real operator name, but used in expressions.
+    {"sZ", "sizeof...", 0},  // Special syntax
     {nullptr, nullptr, 0},
 };
 
@@ -187,9 +192,50 @@ typedef struct {
   int recursion_depth;        // For stack exhaustion prevention.
   int steps;               // Cap how much work we'll do, regardless of depth.
   ParseState parse_state;  // Backtrackable state copied for most frames.
+
+  // Conditionally compiled support for marking the position of the first
+  // construct Demangle couldn't parse.  This preprocessor symbol is intended
+  // for use by Abseil demangler maintainers only; its behavior is not part of
+  // Abseil's public interface.
+#ifdef Y_ABSL_INTERNAL_DEMANGLE_RECORDS_HIGH_WATER_MARK
+  int high_water_mark;  // Input position where parsing failed.
+  bool too_complex;  // True if any guard.IsTooComplex() call returned true.
+#endif
 } State;
 
 namespace {
+
+#ifdef Y_ABSL_INTERNAL_DEMANGLE_RECORDS_HIGH_WATER_MARK
+void UpdateHighWaterMark(State *state) {
+  if (state->high_water_mark < state->parse_state.mangled_idx) {
+    state->high_water_mark = state->parse_state.mangled_idx;
+  }
+}
+
+void ReportHighWaterMark(State *state) {
+  // Write out the mangled name with the trouble point marked, provided that the
+  // output buffer is large enough and the mangled name did not hit a complexity
+  // limit (in which case the high water mark wouldn't point out an unparsable
+  // construct, only the point where a budget ran out).
+  const size_t input_length = std::strlen(state->mangled_begin);
+  if (input_length + 6 > static_cast<size_t>(state->out_end_idx) ||
+      state->too_complex) {
+    if (state->out_end_idx > 0) state->out[0] = '\0';
+    return;
+  }
+  const size_t high_water_mark = static_cast<size_t>(state->high_water_mark);
+  std::memcpy(state->out, state->mangled_begin, high_water_mark);
+  std::memcpy(state->out + high_water_mark, "--!--", 5);
+  std::memcpy(state->out + high_water_mark + 5,
+              state->mangled_begin + high_water_mark,
+              input_length - high_water_mark);
+  state->out[input_length + 5] = '\0';
+}
+#else
+void UpdateHighWaterMark(State *) {}
+void ReportHighWaterMark(State *) {}
+#endif
+
 // Prevent deep recursion / stack exhaustion.
 // Also prevent unbounded handling of complex inputs.
 class ComplexityGuard {
@@ -201,7 +247,7 @@ class ComplexityGuard {
   ~ComplexityGuard() { --state_->recursion_depth; }
 
   // 256 levels of recursion seems like a reasonable upper limit on depth.
-  // 128 is not enough to demagle synthetic tests from demangle_unittest.txt:
+  // 128 is not enough to demangle synthetic tests from demangle_unittest.txt:
   // "_ZaaZZZZ..." and "_ZaaZcvZcvZ..."
   static constexpr int kRecursionDepthLimit = 256;
 
@@ -222,8 +268,14 @@ class ComplexityGuard {
   static constexpr int kParseStepsLimit = 1 << 17;
 
   bool IsTooComplex() const {
-    return state_->recursion_depth > kRecursionDepthLimit ||
-           state_->steps > kParseStepsLimit;
+    if (state_->recursion_depth > kRecursionDepthLimit ||
+        state_->steps > kParseStepsLimit) {
+#ifdef Y_ABSL_INTERNAL_DEMANGLE_RECORDS_HIGH_WATER_MARK
+      state_->too_complex = true;
+#endif
+      return true;
+    }
+    return false;
   }
 
  private:
@@ -270,6 +322,10 @@ static void InitState(State* state,
   state->out_end_idx = static_cast<int>(out_size);
   state->recursion_depth = 0;
   state->steps = 0;
+#ifdef Y_ABSL_INTERNAL_DEMANGLE_RECORDS_HIGH_WATER_MARK
+  state->high_water_mark = 0;
+  state->too_complex = false;
+#endif
 
   state->parse_state.mangled_idx = 0;
   state->parse_state.out_cur_idx = 0;
@@ -291,13 +347,14 @@ static bool ParseOneCharToken(State *state, const char one_char_token) {
   if (guard.IsTooComplex()) return false;
   if (RemainingInput(state)[0] == one_char_token) {
     ++state->parse_state.mangled_idx;
+    UpdateHighWaterMark(state);
     return true;
   }
   return false;
 }
 
-// Returns true and advances "mangled_cur" if we find "two_char_token"
-// at "mangled_cur" position.  It is assumed that "two_char_token" does
+// Returns true and advances "mangled_idx" if we find "two_char_token"
+// at "mangled_idx" position.  It is assumed that "two_char_token" does
 // not contain '\0'.
 static bool ParseTwoCharToken(State *state, const char *two_char_token) {
   ComplexityGuard guard(state);
@@ -305,11 +362,45 @@ static bool ParseTwoCharToken(State *state, const char *two_char_token) {
   if (RemainingInput(state)[0] == two_char_token[0] &&
       RemainingInput(state)[1] == two_char_token[1]) {
     state->parse_state.mangled_idx += 2;
+    UpdateHighWaterMark(state);
     return true;
   }
   return false;
 }
 
+// Returns true and advances "mangled_idx" if we find "three_char_token"
+// at "mangled_idx" position.  It is assumed that "three_char_token" does
+// not contain '\0'.
+static bool ParseThreeCharToken(State *state, const char *three_char_token) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  if (RemainingInput(state)[0] == three_char_token[0] &&
+      RemainingInput(state)[1] == three_char_token[1] &&
+      RemainingInput(state)[2] == three_char_token[2]) {
+    state->parse_state.mangled_idx += 3;
+    UpdateHighWaterMark(state);
+    return true;
+  }
+  return false;
+}
+
+// Returns true and advances "mangled_idx" if we find a copy of the
+// NUL-terminated string "long_token" at "mangled_idx" position.
+static bool ParseLongToken(State *state, const char *long_token) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  int i = 0;
+  for (; long_token[i] != '\0'; ++i) {
+    // Note that we cannot run off the end of the NUL-terminated input here.
+    // Inside the loop body, long_token[i] is known to be different from NUL.
+    // So if we read the NUL on the end of the input here, we return at once.
+    if (RemainingInput(state)[i] != long_token[i]) return false;
+  }
+  state->parse_state.mangled_idx += i;
+  UpdateHighWaterMark(state);
+  return true;
+}
+
 // Returns true and advances "mangled_cur" if we find any character in
 // "char_class" at "mangled_cur" position.
 static bool ParseCharClass(State *state, const char *char_class) {
@@ -322,6 +413,7 @@ static bool ParseCharClass(State *state, const char *char_class) {
   for (; *p != '\0'; ++p) {
     if (RemainingInput(state)[0] == *p) {
       ++state->parse_state.mangled_idx;
+      UpdateHighWaterMark(state);
       return true;
     }
   }
@@ -554,6 +646,7 @@ static bool ParseFloatNumber(State *state);
 static bool ParseSeqId(State *state);
 static bool ParseIdentifier(State *state, size_t length);
 static bool ParseOperatorName(State *state, int *arity);
+static bool ParseConversionOperatorType(State *state);
 static bool ParseSpecialName(State *state);
 static bool ParseCallOffset(State *state);
 static bool ParseNVOffset(State *state);
@@ -563,21 +656,33 @@ static bool ParseCtorDtorName(State *state);
 static bool ParseDecltype(State *state);
 static bool ParseType(State *state);
 static bool ParseCVQualifiers(State *state);
+static bool ParseExtendedQualifier(State *state);
 static bool ParseBuiltinType(State *state);
+static bool ParseVendorExtendedType(State *state);
 static bool ParseFunctionType(State *state);
 static bool ParseBareFunctionType(State *state);
+static bool ParseOverloadAttribute(State *state);
 static bool ParseClassEnumType(State *state);
 static bool ParseArrayType(State *state);
 static bool ParsePointerToMemberType(State *state);
 static bool ParseTemplateParam(State *state);
+static bool ParseTemplateParamDecl(State *state);
 static bool ParseTemplateTemplateParam(State *state);
 static bool ParseTemplateArgs(State *state);
 static bool ParseTemplateArg(State *state);
 static bool ParseBaseUnresolvedName(State *state);
 static bool ParseUnresolvedName(State *state);
+static bool ParseUnresolvedQualifierLevel(State *state);
+static bool ParseUnionSelector(State* state);
+static bool ParseFunctionParam(State* state);
+static bool ParseBracedExpression(State *state);
 static bool ParseExpression(State *state);
+static bool ParseInitializer(State *state);
 static bool ParseExprPrimary(State *state);
-static bool ParseExprCastValue(State *state);
+static bool ParseExprCastValueAndTrailingE(State *state);
+static bool ParseQRequiresClauseExpr(State *state);
+static bool ParseRequirement(State *state);
+static bool ParseTypeConstraint(State *state);
 static bool ParseLocalName(State *state);
 static bool ParseLocalNameSuffix(State *state);
 static bool ParseDiscriminator(State *state);
@@ -622,22 +727,34 @@ static bool ParseMangledName(State *state) {
 }
 
 // <encoding> ::= <(function) name> <bare-function-type>
+//                [`Q` <requires-clause expr>]
 //            ::= <(data) name>
 //            ::= <special-name>
+//
+// NOTE: Based on http://shortn/_Hoq9qG83rx
 static bool ParseEncoding(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
-  // Implementing the first two productions together as <name>
-  // [<bare-function-type>] avoids exponential blowup of backtracking.
+  // Since the first two productions both start with <name>, attempt
+  // to parse it only once to avoid exponential blowup of backtracking.
   //
-  // Since Optional(...) can't fail, there's no need to copy the state for
-  // backtracking.
-  if (ParseName(state) && Optional(ParseBareFunctionType(state))) {
+  // We're careful about exponential blowup because <encoding> recursively
+  // appears in other productions downstream of its first two productions,
+  // which means that every call to `ParseName` would possibly indirectly
+  // result in two calls to `ParseName` etc.
+  if (ParseName(state)) {
+    if (!ParseBareFunctionType(state)) {
+      return true;  // <(data) name>
+    }
+
+    // Parsed: <(function) name> <bare-function-type>
+    // Pending: [`Q` <requires-clause expr>]
+    ParseQRequiresClauseExpr(state);  // restores state on failure
     return true;
   }
 
   if (ParseSpecialName(state)) {
-    return true;
+    return true;  // <special-name>
   }
   return false;
 }
@@ -723,19 +840,26 @@ static bool ParseNestedName(State *state) {
 // <prefix> ::= <prefix> <unqualified-name>
 //          ::= <template-prefix> <template-args>
 //          ::= <template-param>
+//          ::= <decltype>
 //          ::= <substitution>
 //          ::= # empty
 // <template-prefix> ::= <prefix> <(template) unqualified-name>
 //                   ::= <template-param>
 //                   ::= <substitution>
+//                   ::= <vendor-extended-type>
 static bool ParsePrefix(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   bool has_something = false;
   while (true) {
     MaybeAppendSeparator(state);
-    if (ParseTemplateParam(state) ||
+    if (ParseTemplateParam(state) || ParseDecltype(state) ||
         ParseSubstitution(state, /*accept_std=*/true) ||
+        // Although the official grammar does not mention it, nested-names
+        // shaped like Nu14__some_builtinIiE6memberE occur in practice, and it
+        // is not clear what else a compiler is supposed to do when a
+        // vendor-extended type has named members.
+        ParseVendorExtendedType(state) ||
         ParseUnscopedName(state) ||
         (ParseOneCharToken(state, 'M') && ParseUnnamedTypeName(state))) {
       has_something = true;
@@ -757,8 +881,14 @@ static bool ParsePrefix(State *state) {
 //                    ::= <source-name> [<abi-tags>]
 //                    ::= <local-source-name> [<abi-tags>]
 //                    ::= <unnamed-type-name> [<abi-tags>]
+//                    ::= DC <source-name>+ E  # C++17 structured binding
+//                    ::= F <source-name>  # C++20 constrained friend
+//                    ::= F <operator-name>  # C++20 constrained friend
 //
 // <local-source-name> is a GCC extension; see below.
+//
+// For the F notation for constrained friends, see
+// https://github.com/itanium-cxx-abi/cxx-abi/issues/24#issuecomment-1491130332.
 static bool ParseUnqualifiedName(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
@@ -767,6 +897,23 @@ static bool ParseUnqualifiedName(State *state) {
       ParseUnnamedTypeName(state)) {
     return ParseAbiTags(state);
   }
+
+  // DC <source-name>+ E
+  ParseState copy = state->parse_state;
+  if (ParseTwoCharToken(state, "DC") && OneOrMore(ParseSourceName, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // F <source-name>
+  // F <operator-name>
+  if (ParseOneCharToken(state, 'F') && MaybeAppend(state, "friend ") &&
+      (ParseSourceName(state) || ParseOperatorName(state, nullptr))) {
+    return true;
+  }
+  state->parse_state = copy;
+
   return false;
 }
 
@@ -824,7 +971,11 @@ static bool ParseLocalSourceName(State *state) {
 // <unnamed-type-name> ::= Ut [<(nonnegative) number>] _
 //                     ::= <closure-type-name>
 // <closure-type-name> ::= Ul <lambda-sig> E [<(nonnegative) number>] _
-// <lambda-sig>        ::= <(parameter) type>+
+// <lambda-sig>        ::= <template-param-decl>* <(parameter) type>+
+//
+// For <template-param-decl>* in <lambda-sig> see:
+//
+// https://github.com/itanium-cxx-abi/cxx-abi/issues/31
 static bool ParseUnnamedTypeName(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
@@ -847,6 +998,7 @@ static bool ParseUnnamedTypeName(State *state) {
   // Closure type.
   which = -1;
   if (ParseTwoCharToken(state, "Ul") && DisableAppend(state) &&
+      ZeroOrMore(ParseTemplateParamDecl, state) &&
       OneOrMore(ParseType, state) && RestoreAppend(state, copy.append) &&
       ParseOneCharToken(state, 'E') && Optional(ParseNumber(state, &which)) &&
       which <= std::numeric_limits<int>::max() - 2 &&  // Don't overflow.
@@ -888,6 +1040,7 @@ static bool ParseNumber(State *state, int *number_out) {
   }
   if (p != RemainingInput(state)) {  // Conversion succeeded.
     state->parse_state.mangled_idx += p - RemainingInput(state);
+    UpdateHighWaterMark(state);
     if (number_out != nullptr) {
       // Note: possibly truncate "number".
       *number_out = static_cast<int>(number);
@@ -910,6 +1063,7 @@ static bool ParseFloatNumber(State *state) {
   }
   if (p != RemainingInput(state)) {  // Conversion succeeded.
     state->parse_state.mangled_idx += p - RemainingInput(state);
+    UpdateHighWaterMark(state);
     return true;
   }
   return false;
@@ -928,6 +1082,7 @@ static bool ParseSeqId(State *state) {
   }
   if (p != RemainingInput(state)) {  // Conversion succeeded.
     state->parse_state.mangled_idx += p - RemainingInput(state);
+    UpdateHighWaterMark(state);
     return true;
   }
   return false;
@@ -946,11 +1101,13 @@ static bool ParseIdentifier(State *state, size_t length) {
     MaybeAppendWithLength(state, RemainingInput(state), length);
   }
   state->parse_state.mangled_idx += length;
+  UpdateHighWaterMark(state);
   return true;
 }
 
 // <operator-name> ::= nw, and other two letters cases
 //                 ::= cv <type>  # (cast)
+//                 ::= li <source-name>  # C++11 user-defined literal
 //                 ::= v  <digit> <source-name> # vendor extended operator
 static bool ParseOperatorName(State *state, int *arity) {
   ComplexityGuard guard(state);
@@ -961,7 +1118,7 @@ static bool ParseOperatorName(State *state, int *arity) {
   // First check with "cv" (cast) case.
   ParseState copy = state->parse_state;
   if (ParseTwoCharToken(state, "cv") && MaybeAppend(state, "operator ") &&
-      EnterNestedName(state) && ParseType(state) &&
+      EnterNestedName(state) && ParseConversionOperatorType(state) &&
       LeaveNestedName(state, copy.nest_level)) {
     if (arity != nullptr) {
       *arity = 1;
@@ -970,6 +1127,13 @@ static bool ParseOperatorName(State *state, int *arity) {
   }
   state->parse_state = copy;
 
+  // Then user-defined literals.
+  if (ParseTwoCharToken(state, "li") && MaybeAppend(state, "operator\"\" ") &&
+      ParseSourceName(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   // Then vendor extended operators.
   if (ParseOneCharToken(state, 'v') && ParseDigit(state, arity) &&
       ParseSourceName(state)) {
@@ -997,36 +1161,120 @@ static bool ParseOperatorName(State *state, int *arity) {
       }
       MaybeAppend(state, p->real_name);
       state->parse_state.mangled_idx += 2;
+      UpdateHighWaterMark(state);
       return true;
     }
   }
   return false;
 }
 
+// <operator-name> ::= cv <type>  # (cast)
+//
+// The name of a conversion operator is the one place where cv-qualifiers, *, &,
+// and other simple type combinators are expected to appear in our stripped-down
+// demangling (elsewhere they appear in function signatures or template
+// arguments, which we omit from the output).  We make reasonable efforts to
+// render simple cases accurately.
+static bool ParseConversionOperatorType(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+
+  // Scan pointers, const, and other easy mangling prefixes with postfix
+  // demanglings.  Remember the range of input for later rescanning.
+  //
+  // See `ParseType` and the `switch` below for the meaning of each char.
+  const char* begin_simple_prefixes = RemainingInput(state);
+  while (ParseCharClass(state, "OPRCGrVK")) {}
+  const char* end_simple_prefixes = RemainingInput(state);
+
+  // Emit the base type first.
+  if (!ParseType(state)) {
+    state->parse_state = copy;
+    return false;
+  }
+
+  // Then rescan the easy type combinators in reverse order to emit their
+  // demanglings in the expected output order.
+  while (begin_simple_prefixes != end_simple_prefixes) {
+    switch (*--end_simple_prefixes) {
+      case 'P':
+        MaybeAppend(state, "*");
+        break;
+      case 'R':
+        MaybeAppend(state, "&");
+        break;
+      case 'O':
+        MaybeAppend(state, "&&");
+        break;
+      case 'C':
+        MaybeAppend(state, " _Complex");
+        break;
+      case 'G':
+        MaybeAppend(state, " _Imaginary");
+        break;
+      case 'r':
+        MaybeAppend(state, " restrict");
+        break;
+      case 'V':
+        MaybeAppend(state, " volatile");
+        break;
+      case 'K':
+        MaybeAppend(state, " const");
+        break;
+    }
+  }
+  return true;
+}
+
 // <special-name> ::= TV <type>
 //                ::= TT <type>
 //                ::= TI <type>
 //                ::= TS <type>
-//                ::= TH <type>  # thread-local
+//                ::= TW <name>  # thread-local wrapper
+//                ::= TH <name>  # thread-local initialization
 //                ::= Tc <call-offset> <call-offset> <(base) encoding>
 //                ::= GV <(object) name>
+//                ::= GR <(object) name> [<seq-id>] _
 //                ::= T <call-offset> <(base) encoding>
+//                ::= GTt <encoding>  # transaction-safe entry point
+//                ::= TA <template-arg>  # nontype template parameter object
 // G++ extensions:
 //                ::= TC <type> <(offset) number> _ <(base) type>
 //                ::= TF <type>
 //                ::= TJ <type>
-//                ::= GR <name>
+//                ::= GR <name>  # without final _, perhaps an earlier form?
 //                ::= GA <encoding>
 //                ::= Th <call-offset> <(base) encoding>
 //                ::= Tv <call-offset> <(base) encoding>
 //
-// Note: we don't care much about them since they don't appear in
-// stack traces.  The are special data.
+// Note: Most of these are special data, not functions that occur in stack
+// traces.  Exceptions are TW and TH, which denote functions supporting the
+// thread_local feature.  For these see:
+//
+// https://maskray.me/blog/2021-02-14-all-about-thread-local-storage
+//
+// For TA see https://github.com/itanium-cxx-abi/cxx-abi/issues/63.
 static bool ParseSpecialName(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   ParseState copy = state->parse_state;
-  if (ParseOneCharToken(state, 'T') && ParseCharClass(state, "VTISH") &&
+
+  if (ParseTwoCharToken(state, "TW")) {
+    MaybeAppend(state, "thread-local wrapper routine for ");
+    if (ParseName(state)) return true;
+    state->parse_state = copy;
+    return false;
+  }
+
+  if (ParseTwoCharToken(state, "TH")) {
+    MaybeAppend(state, "thread-local initialization routine for ");
+    if (ParseName(state)) return true;
+    state->parse_state = copy;
+    return false;
+  }
+
+  if (ParseOneCharToken(state, 'T') && ParseCharClass(state, "VTIS") &&
       ParseType(state)) {
     return true;
   }
@@ -1064,21 +1312,51 @@ static bool ParseSpecialName(State *state) {
   }
   state->parse_state = copy;
 
-  if (ParseTwoCharToken(state, "GR") && ParseName(state)) {
+  // <special-name> ::= GR <(object) name> [<seq-id>] _  # modern standard
+  //                ::= GR <(object) name>  # also recognized
+  if (ParseTwoCharToken(state, "GR")) {
+    MaybeAppend(state, "reference temporary for ");
+    if (!ParseName(state)) {
+      state->parse_state = copy;
+      return false;
+    }
+    const bool has_seq_id = ParseSeqId(state);
+    const bool has_underscore = ParseOneCharToken(state, '_');
+    if (has_seq_id && !has_underscore) {
+      state->parse_state = copy;
+      return false;
+    }
     return true;
   }
-  state->parse_state = copy;
 
   if (ParseTwoCharToken(state, "GA") && ParseEncoding(state)) {
     return true;
   }
   state->parse_state = copy;
 
+  if (ParseThreeCharToken(state, "GTt") &&
+      MaybeAppend(state, "transaction clone for ") && ParseEncoding(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   if (ParseOneCharToken(state, 'T') && ParseCharClass(state, "hv") &&
       ParseCallOffset(state) && ParseEncoding(state)) {
     return true;
   }
   state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "TA")) {
+    bool append = state->parse_state.append;
+    DisableAppend(state);
+    if (ParseTemplateArg(state)) {
+      RestoreAppend(state, append);
+      MaybeAppend(state, "template parameter object");
+      return true;
+    }
+  }
+  state->parse_state = copy;
+
   return false;
 }
 
@@ -1182,7 +1460,6 @@ static bool ParseDecltype(State *state) {
 //        ::= O <type>   # rvalue reference-to (C++0x)
 //        ::= C <type>   # complex pair (C 2000)
 //        ::= G <type>   # imaginary (C 2000)
-//        ::= U <source-name> <type>  # vendor extended type qualifier
 //        ::= <builtin-type>
 //        ::= <function-type>
 //        ::= <class-enum-type>  # note: just an alias for <name>
@@ -1193,7 +1470,9 @@ static bool ParseDecltype(State *state) {
 //        ::= <decltype>
 //        ::= <substitution>
 //        ::= Dp <type>          # pack expansion of (C++0x)
-//        ::= Dv <num-elems> _   # GNU vector extension
+//        ::= Dv <(elements) number> _ <type>  # GNU vector extension
+//        ::= Dv <(bytes) expression> _ <type>
+//        ::= Dk <type-constraint>  # constrained auto
 //
 static bool ParseType(State *state) {
   ComplexityGuard guard(state);
@@ -1236,12 +1515,6 @@ static bool ParseType(State *state) {
   }
   state->parse_state = copy;
 
-  if (ParseOneCharToken(state, 'U') && ParseSourceName(state) &&
-      ParseType(state)) {
-    return true;
-  }
-  state->parse_state = copy;
-
   if (ParseBuiltinType(state) || ParseFunctionType(state) ||
       ParseClassEnumType(state) || ParseArrayType(state) ||
       ParsePointerToMemberType(state) || ParseDecltype(state) ||
@@ -1260,54 +1533,160 @@ static bool ParseType(State *state) {
     return true;
   }
 
+  // GNU vector extension Dv <number> _ <type>
   if (ParseTwoCharToken(state, "Dv") && ParseNumber(state, nullptr) &&
-      ParseOneCharToken(state, '_')) {
+      ParseOneCharToken(state, '_') && ParseType(state)) {
     return true;
   }
   state->parse_state = copy;
 
-  return false;
+  // GNU vector extension Dv <expression> _ <type>
+  if (ParseTwoCharToken(state, "Dv") && ParseExpression(state) &&
+      ParseOneCharToken(state, '_') && ParseType(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "Dk") && ParseTypeConstraint(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // For this notation see CXXNameMangler::mangleType in Clang's source code.
+  // The relevant logic and its comment "not clear how to mangle this!" date
+  // from 2011, so it may be with us awhile.
+  return ParseLongToken(state, "_SUBSTPACK_");
 }
 
+// <qualifiers> ::= <extended-qualifier>* <CV-qualifiers>
 // <CV-qualifiers> ::= [r] [V] [K]
+//
 // We don't allow empty <CV-qualifiers> to avoid infinite loop in
 // ParseType().
 static bool ParseCVQualifiers(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   int num_cv_qualifiers = 0;
+  while (ParseExtendedQualifier(state)) ++num_cv_qualifiers;
   num_cv_qualifiers += ParseOneCharToken(state, 'r');
   num_cv_qualifiers += ParseOneCharToken(state, 'V');
   num_cv_qualifiers += ParseOneCharToken(state, 'K');
   return num_cv_qualifiers > 0;
 }
 
+// <extended-qualifier> ::= U <source-name> [<template-args>]
+static bool ParseExtendedQualifier(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+
+  if (!ParseOneCharToken(state, 'U')) return false;
+
+  bool append = state->parse_state.append;
+  DisableAppend(state);
+  if (!ParseSourceName(state)) {
+    state->parse_state = copy;
+    return false;
+  }
+  Optional(ParseTemplateArgs(state));
+  RestoreAppend(state, append);
+  return true;
+}
+
 // <builtin-type> ::= v, etc.  # single-character builtin types
-//                ::= u <source-name>
+//                ::= <vendor-extended-type>
 //                ::= Dd, etc.  # two-character builtin types
+//                ::= DB (<number> | <expression>) _  # _BitInt(N)
+//                ::= DU (<number> | <expression>) _  # unsigned _BitInt(N)
+//                ::= DF <number> _  # _FloatN (N bits)
+//                ::= DF <number> x  # _FloatNx
+//                ::= DF16b  # std::bfloat16_t
 //
 // Not supported:
-//                ::= DF <number> _ # _FloatN (N bits)
-//
+//                ::= [DS] DA <fixed-point-size>
+//                ::= [DS] DR <fixed-point-size>
+// because real implementations of N1169 fixed-point are scant.
 static bool ParseBuiltinType(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
-  const AbbrevPair *p;
-  for (p = kBuiltinTypeList; p->abbrev != nullptr; ++p) {
+  ParseState copy = state->parse_state;
+
+  // DB (<number> | <expression>) _  # _BitInt(N)
+  // DU (<number> | <expression>) _  # unsigned _BitInt(N)
+  if (ParseTwoCharToken(state, "DB") ||
+      (ParseTwoCharToken(state, "DU") && MaybeAppend(state, "unsigned "))) {
+    bool append = state->parse_state.append;
+    DisableAppend(state);
+    int number = -1;
+    if (!ParseNumber(state, &number) && !ParseExpression(state)) {
+      state->parse_state = copy;
+      return false;
+    }
+    RestoreAppend(state, append);
+
+    if (!ParseOneCharToken(state, '_')) {
+      state->parse_state = copy;
+      return false;
+    }
+
+    MaybeAppend(state, "_BitInt(");
+    if (number >= 0) {
+      MaybeAppendDecimal(state, number);
+    } else {
+      MaybeAppend(state, "?");  // the best we can do for dependent sizes
+    }
+    MaybeAppend(state, ")");
+    return true;
+  }
+
+  // DF <number> _  # _FloatN
+  // DF <number> x  # _FloatNx
+  // DF16b  # std::bfloat16_t
+  if (ParseTwoCharToken(state, "DF")) {
+    if (ParseThreeCharToken(state, "16b")) {
+      MaybeAppend(state, "std::bfloat16_t");
+      return true;
+    }
+    int number = 0;
+    if (!ParseNumber(state, &number)) {
+      state->parse_state = copy;
+      return false;
+    }
+    MaybeAppend(state, "_Float");
+    MaybeAppendDecimal(state, number);
+    if (ParseOneCharToken(state, 'x')) {
+      MaybeAppend(state, "x");
+      return true;
+    }
+    if (ParseOneCharToken(state, '_')) return true;
+    state->parse_state = copy;
+    return false;
+  }
+
+  for (const AbbrevPair *p = kBuiltinTypeList; p->abbrev != nullptr; ++p) {
     // Guaranteed only 1- or 2-character strings in kBuiltinTypeList.
     if (p->abbrev[1] == '\0') {
       if (ParseOneCharToken(state, p->abbrev[0])) {
         MaybeAppend(state, p->real_name);
-        return true;
+        return true;  // ::= v, etc.  # single-character builtin types
       }
     } else if (p->abbrev[2] == '\0' && ParseTwoCharToken(state, p->abbrev)) {
       MaybeAppend(state, p->real_name);
-      return true;
+      return true;  // ::= Dd, etc.  # two-character builtin types
     }
   }
 
+  return ParseVendorExtendedType(state);
+}
+
+// <vendor-extended-type> ::= u <source-name> [<template-args>]
+static bool ParseVendorExtendedType(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+
   ParseState copy = state->parse_state;
-  if (ParseOneCharToken(state, 'u') && ParseSourceName(state)) {
+  if (ParseOneCharToken(state, 'u') && ParseSourceName(state) &&
+      Optional(ParseTemplateArgs(state))) {
     return true;
   }
   state->parse_state = copy;
@@ -1342,28 +1721,44 @@ static bool ParseExceptionSpec(State *state) {
   return false;
 }
 
-// <function-type> ::= [exception-spec] F [Y] <bare-function-type> [O] E
+// <function-type> ::=
+//     [exception-spec] [Dx] F [Y] <bare-function-type> [<ref-qualifier>] E
+//
+// <ref-qualifier> ::= R | O
 static bool ParseFunctionType(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   ParseState copy = state->parse_state;
-  if (Optional(ParseExceptionSpec(state)) && ParseOneCharToken(state, 'F') &&
-      Optional(ParseOneCharToken(state, 'Y')) && ParseBareFunctionType(state) &&
-      Optional(ParseOneCharToken(state, 'O')) &&
-      ParseOneCharToken(state, 'E')) {
-    return true;
+  Optional(ParseExceptionSpec(state));
+  Optional(ParseTwoCharToken(state, "Dx"));
+  if (!ParseOneCharToken(state, 'F')) {
+    state->parse_state = copy;
+    return false;
   }
-  state->parse_state = copy;
-  return false;
+  Optional(ParseOneCharToken(state, 'Y'));
+  if (!ParseBareFunctionType(state)) {
+    state->parse_state = copy;
+    return false;
+  }
+  Optional(ParseCharClass(state, "RO"));
+  if (!ParseOneCharToken(state, 'E')) {
+    state->parse_state = copy;
+    return false;
+  }
+  return true;
 }
 
-// <bare-function-type> ::= <(signature) type>+
+// <bare-function-type> ::= <overload-attribute>* <(signature) type>+
+//
+// The <overload-attribute>* prefix is nonstandard; see the comment on
+// ParseOverloadAttribute.
 static bool ParseBareFunctionType(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   ParseState copy = state->parse_state;
   DisableAppend(state);
-  if (OneOrMore(ParseType, state)) {
+  if (ZeroOrMore(ParseOverloadAttribute, state) &&
+      OneOrMore(ParseType, state)) {
     RestoreAppend(state, copy.append);
     MaybeAppend(state, "()");
     return true;
@@ -1372,11 +1767,43 @@ static bool ParseBareFunctionType(State *state) {
   return false;
 }
 
+// <overload-attribute> ::= Ua <name>
+//
+// The nonstandard <overload-attribute> production is sufficient to accept the
+// current implementation of __attribute__((enable_if(condition, "message")))
+// and future attributes of a similar shape.  See
+// https://clang.llvm.org/docs/AttributeReference.html#enable-if and the
+// definition of CXXNameMangler::mangleFunctionEncodingBareType in Clang's
+// source code.
+static bool ParseOverloadAttribute(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+  if (ParseTwoCharToken(state, "Ua") && ParseName(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+  return false;
+}
+
 // <class-enum-type> ::= <name>
+//                   ::= Ts <name>  # struct Name or class Name
+//                   ::= Tu <name>  # union Name
+//                   ::= Te <name>  # enum Name
+//
+// See http://shortn/_W3YrltiEd0.
 static bool ParseClassEnumType(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
-  return ParseName(state);
+  ParseState copy = state->parse_state;
+  if (Optional(ParseTwoCharToken(state, "Ts") ||
+               ParseTwoCharToken(state, "Tu") ||
+               ParseTwoCharToken(state, "Te")) &&
+      ParseName(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+  return false;
 }
 
 // <array-type> ::= A <(positive dimension) number> _ <(element) type>
@@ -1413,21 +1840,83 @@ static bool ParsePointerToMemberType(State *state) {
 
 // <template-param> ::= T_
 //                  ::= T <parameter-2 non-negative number> _
+//                  ::= TL <level-1> __
+//                  ::= TL <level-1> _ <parameter-2 non-negative number> _
 static bool ParseTemplateParam(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   if (ParseTwoCharToken(state, "T_")) {
     MaybeAppend(state, "?");  // We don't support template substitutions.
-    return true;
+    return true;              // ::= T_
   }
 
   ParseState copy = state->parse_state;
   if (ParseOneCharToken(state, 'T') && ParseNumber(state, nullptr) &&
       ParseOneCharToken(state, '_')) {
     MaybeAppend(state, "?");  // We don't support template substitutions.
+    return true;              // ::= T <parameter-2 non-negative number> _
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "TL") && ParseNumber(state, nullptr)) {
+    if (ParseTwoCharToken(state, "__")) {
+      MaybeAppend(state, "?");  // We don't support template substitutions.
+      return true;              // ::= TL <level-1> __
+    }
+
+    if (ParseOneCharToken(state, '_') && ParseNumber(state, nullptr) &&
+        ParseOneCharToken(state, '_')) {
+      MaybeAppend(state, "?");  // We don't support template substitutions.
+      return true;  // ::= TL <level-1> _ <parameter-2 non-negative number> _
+    }
+  }
+  state->parse_state = copy;
+  return false;
+}
+
+// <template-param-decl>
+//   ::= Ty                                  # template type parameter
+//   ::= Tk <concept name> [<template-args>] # constrained type parameter
+//   ::= Tn <type>                           # template non-type parameter
+//   ::= Tt <template-param-decl>* E         # template template parameter
+//   ::= Tp <template-param-decl>            # template parameter pack
+//
+// NOTE: <concept name> is just a <name>: http://shortn/_MqJVyr0fc1
+// TODO(b/324066279): Implement optional suffix for `Tt`:
+// [Q <requires-clause expr>]
+static bool ParseTemplateParamDecl(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+
+  if (ParseTwoCharToken(state, "Ty")) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "Tk") && ParseName(state) &&
+      Optional(ParseTemplateArgs(state))) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "Tn") && ParseType(state)) {
     return true;
   }
   state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "Tt") &&
+      ZeroOrMore(ParseTemplateParamDecl, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "Tp") && ParseTemplateParamDecl(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   return false;
 }
 
@@ -1441,13 +1930,14 @@ static bool ParseTemplateTemplateParam(State *state) {
           ParseSubstitution(state, /*accept_std=*/false));
 }
 
-// <template-args> ::= I <template-arg>+ E
+// <template-args> ::= I <template-arg>+ [Q <requires-clause expr>] E
 static bool ParseTemplateArgs(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   ParseState copy = state->parse_state;
   DisableAppend(state);
   if (ParseOneCharToken(state, 'I') && OneOrMore(ParseTemplateArg, state) &&
+      Optional(ParseQRequiresClauseExpr(state)) &&
       ParseOneCharToken(state, 'E')) {
     RestoreAppend(state, copy.append);
     MaybeAppend(state, "<>");
@@ -1457,7 +1947,8 @@ static bool ParseTemplateArgs(State *state) {
   return false;
 }
 
-// <template-arg>  ::= <type>
+// <template-arg>  ::= <template-param-decl> <template-arg>
+//                 ::= <type>
 //                 ::= <expr-primary>
 //                 ::= J <template-arg>* E        # argument pack
 //                 ::= X <expression> E
@@ -1541,7 +2032,7 @@ static bool ParseTemplateArg(State *state) {
   //     ::= L <source-name> [<template-args>] [<expr-cast-value> E]
   if (ParseLocalSourceName(state) && Optional(ParseTemplateArgs(state))) {
     copy = state->parse_state;
-    if (ParseExprCastValue(state) && ParseOneCharToken(state, 'E')) {
+    if (ParseExprCastValueAndTrailingE(state)) {
       return true;
     }
     state->parse_state = copy;
@@ -1560,6 +2051,12 @@ static bool ParseTemplateArg(State *state) {
     return true;
   }
   state->parse_state = copy;
+
+  if (ParseTemplateParamDecl(state) && ParseTemplateArg(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   return false;
 }
 
@@ -1614,6 +2111,13 @@ static bool ParseBaseUnresolvedName(State *state) {
 //                         <base-unresolved-name>
 //                   ::= [gs] sr <unresolved-qualifier-level>+ E
 //                         <base-unresolved-name>
+//                   ::= sr St <simple-id> <simple-id>  # nonstandard
+//
+// The last case is not part of the official grammar but has been observed in
+// real-world examples that the GNU demangler (but not the LLVM demangler) is
+// able to decode; see demangle_test.cc for one such symbol name.  The shape
+// sr St <simple-id> <simple-id> was inferred by closed-box testing of the GNU
+// demangler.
 static bool ParseUnresolvedName(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
@@ -1633,7 +2137,7 @@ static bool ParseUnresolvedName(State *state) {
 
   if (ParseTwoCharToken(state, "sr") && ParseOneCharToken(state, 'N') &&
       ParseUnresolvedType(state) &&
-      OneOrMore(/* <unresolved-qualifier-level> ::= */ ParseSimpleId, state) &&
+      OneOrMore(ParseUnresolvedQualifierLevel, state) &&
       ParseOneCharToken(state, 'E') && ParseBaseUnresolvedName(state)) {
     return true;
   }
@@ -1641,35 +2145,160 @@ static bool ParseUnresolvedName(State *state) {
 
   if (Optional(ParseTwoCharToken(state, "gs")) &&
       ParseTwoCharToken(state, "sr") &&
-      OneOrMore(/* <unresolved-qualifier-level> ::= */ ParseSimpleId, state) &&
+      OneOrMore(ParseUnresolvedQualifierLevel, state) &&
       ParseOneCharToken(state, 'E') && ParseBaseUnresolvedName(state)) {
     return true;
   }
   state->parse_state = copy;
 
+  if (ParseTwoCharToken(state, "sr") && ParseTwoCharToken(state, "St") &&
+      ParseSimpleId(state) && ParseSimpleId(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   return false;
 }
 
+// <unresolved-qualifier-level> ::= <simple-id>
+//                              ::= <substitution> <template-args>
+//
+// The production <substitution> <template-args> is nonstandard but is observed
+// in practice.  An upstream discussion on the best shape of <unresolved-name>
+// has not converged:
+//
+// https://github.com/itanium-cxx-abi/cxx-abi/issues/38
+static bool ParseUnresolvedQualifierLevel(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+
+  if (ParseSimpleId(state)) return true;
+
+  ParseState copy = state->parse_state;
+  if (ParseSubstitution(state, /*accept_std=*/false) &&
+      ParseTemplateArgs(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+  return false;
+}
+
+// <union-selector> ::= _ [<number>]
+//
+// https://github.com/itanium-cxx-abi/cxx-abi/issues/47
+static bool ParseUnionSelector(State *state) {
+  return ParseOneCharToken(state, '_') && Optional(ParseNumber(state, nullptr));
+}
+
+// <function-param> ::= fp <(top-level) CV-qualifiers> _
+//                  ::= fp <(top-level) CV-qualifiers> <number> _
+//                  ::= fL <number> p <(top-level) CV-qualifiers> _
+//                  ::= fL <number> p <(top-level) CV-qualifiers> <number> _
+//                  ::= fpT  # this
+static bool ParseFunctionParam(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+
+  ParseState copy = state->parse_state;
+
+  // Function-param expression (level 0).
+  if (ParseTwoCharToken(state, "fp") && Optional(ParseCVQualifiers(state)) &&
+      Optional(ParseNumber(state, nullptr)) && ParseOneCharToken(state, '_')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // Function-param expression (level 1+).
+  if (ParseTwoCharToken(state, "fL") && Optional(ParseNumber(state, nullptr)) &&
+      ParseOneCharToken(state, 'p') && Optional(ParseCVQualifiers(state)) &&
+      Optional(ParseNumber(state, nullptr)) && ParseOneCharToken(state, '_')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  return ParseThreeCharToken(state, "fpT");
+}
+
+// <braced-expression> ::= <expression>
+//                     ::= di <field source-name> <braced-expression>
+//                     ::= dx <index expression> <braced-expression>
+//                     ::= dX <expression> <expression> <braced-expression>
+static bool ParseBracedExpression(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+
+  ParseState copy = state->parse_state;
+
+  if (ParseTwoCharToken(state, "di") && ParseSourceName(state) &&
+      ParseBracedExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "dx") && ParseExpression(state) &&
+      ParseBracedExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "dX") &&
+      ParseExpression(state) && ParseExpression(state) &&
+      ParseBracedExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  return ParseExpression(state);
+}
+
 // <expression> ::= <1-ary operator-name> <expression>
 //              ::= <2-ary operator-name> <expression> <expression>
 //              ::= <3-ary operator-name> <expression> <expression> <expression>
+//              ::= pp_ <expression>  # ++e; pp <expression> is e++
+//              ::= mm_ <expression>  # --e; mm <expression> is e--
 //              ::= cl <expression>+ E
 //              ::= cp <simple-id> <expression>* E # Clang-specific.
+//              ::= so <type> <expression> [<number>] <union-selector>* [p] E
 //              ::= cv <type> <expression>      # type (expression)
 //              ::= cv <type> _ <expression>* E # type (expr-list)
+//              ::= tl <type> <braced-expression>* E
+//              ::= il <braced-expression>* E
+//              ::= [gs] nw <expression>* _ <type> E
+//              ::= [gs] nw <expression>* _ <type> <initializer>
+//              ::= [gs] na <expression>* _ <type> E
+//              ::= [gs] na <expression>* _ <type> <initializer>
+//              ::= [gs] dl <expression>
+//              ::= [gs] da <expression>
+//              ::= dc <type> <expression>
+//              ::= sc <type> <expression>
+//              ::= cc <type> <expression>
+//              ::= rc <type> <expression>
+//              ::= ti <type>
+//              ::= te <expression>
 //              ::= st <type>
+//              ::= at <type>
+//              ::= az <expression>
+//              ::= nx <expression>
 //              ::= <template-param>
 //              ::= <function-param>
+//              ::= sZ <template-param>
+//              ::= sZ <function-param>
+//              ::= sP <template-arg>* E
 //              ::= <expr-primary>
 //              ::= dt <expression> <unresolved-name> # expr.name
 //              ::= pt <expression> <unresolved-name> # expr->name
 //              ::= sp <expression>         # argument pack expansion
+//              ::= fl <binary operator-name> <expression>
+//              ::= fr <binary operator-name> <expression>
+//              ::= fL <binary operator-name> <expression> <expression>
+//              ::= fR <binary operator-name> <expression> <expression>
+//              ::= tw <expression>
+//              ::= tr
 //              ::= sr <type> <unqualified-name> <template-args>
 //              ::= sr <type> <unqualified-name>
-// <function-param> ::= fp <(top-level) CV-qualifiers> _
-//                  ::= fp <(top-level) CV-qualifiers> <number> _
-//                  ::= fL <number> p <(top-level) CV-qualifiers> _
-//                  ::= fL <number> p <(top-level) CV-qualifiers> <number> _
+//              ::= u <source-name> <template-arg>* E  # vendor extension
+//              ::= rq <requirement>+ E
+//              ::= rQ <bare-function-type> _ <requirement>+ E
 static bool ParseExpression(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
@@ -1686,6 +2315,15 @@ static bool ParseExpression(State *state) {
   }
   state->parse_state = copy;
 
+  // Preincrement and predecrement.  Postincrement and postdecrement are handled
+  // by the operator-name logic later on.
+  if ((ParseThreeCharToken(state, "pp_") ||
+       ParseThreeCharToken(state, "mm_")) &&
+      ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   // Clang-specific "cp <simple-id> <expression>* E"
   //   https://clang.llvm.org/doxygen/ItaniumMangle_8cpp_source.html#l04338
   if (ParseTwoCharToken(state, "cp") && ParseSimpleId(state) &&
@@ -1694,17 +2332,65 @@ static bool ParseExpression(State *state) {
   }
   state->parse_state = copy;
 
-  // Function-param expression (level 0).
-  if (ParseTwoCharToken(state, "fp") && Optional(ParseCVQualifiers(state)) &&
-      Optional(ParseNumber(state, nullptr)) && ParseOneCharToken(state, '_')) {
+  // <expression> ::= so <type> <expression> [<number>] <union-selector>* [p] E
+  //
+  // https://github.com/itanium-cxx-abi/cxx-abi/issues/47
+  if (ParseTwoCharToken(state, "so") && ParseType(state) &&
+      ParseExpression(state) && Optional(ParseNumber(state, nullptr)) &&
+      ZeroOrMore(ParseUnionSelector, state) &&
+      Optional(ParseOneCharToken(state, 'p')) &&
+      ParseOneCharToken(state, 'E')) {
     return true;
   }
   state->parse_state = copy;
 
-  // Function-param expression (level 1+).
-  if (ParseTwoCharToken(state, "fL") && Optional(ParseNumber(state, nullptr)) &&
-      ParseOneCharToken(state, 'p') && Optional(ParseCVQualifiers(state)) &&
-      Optional(ParseNumber(state, nullptr)) && ParseOneCharToken(state, '_')) {
+  // <expression> ::= <function-param>
+  if (ParseFunctionParam(state)) return true;
+  state->parse_state = copy;
+
+  // <expression> ::= tl <type> <braced-expression>* E
+  if (ParseTwoCharToken(state, "tl") && ParseType(state) &&
+      ZeroOrMore(ParseBracedExpression, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // <expression> ::= il <braced-expression>* E
+  if (ParseTwoCharToken(state, "il") &&
+      ZeroOrMore(ParseBracedExpression, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // <expression> ::= [gs] nw <expression>* _ <type> E
+  //              ::= [gs] nw <expression>* _ <type> <initializer>
+  //              ::= [gs] na <expression>* _ <type> E
+  //              ::= [gs] na <expression>* _ <type> <initializer>
+  if (Optional(ParseTwoCharToken(state, "gs")) &&
+      (ParseTwoCharToken(state, "nw") || ParseTwoCharToken(state, "na")) &&
+      ZeroOrMore(ParseExpression, state) && ParseOneCharToken(state, '_') &&
+      ParseType(state) &&
+      (ParseOneCharToken(state, 'E') || ParseInitializer(state))) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // <expression> ::= [gs] dl <expression>
+  //              ::= [gs] da <expression>
+  if (Optional(ParseTwoCharToken(state, "gs")) &&
+      (ParseTwoCharToken(state, "dl") || ParseTwoCharToken(state, "da")) &&
+      ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // dynamic_cast, static_cast, const_cast, reinterpret_cast.
+  //
+  // <expression> ::= (dc | sc | cc | rc) <type> <expression>
+  if (ParseCharClass(state, "dscr") && ParseOneCharToken(state, 'c') &&
+      ParseType(state) && ParseExpression(state)) {
     return true;
   }
   state->parse_state = copy;
@@ -1746,15 +2432,96 @@ static bool ParseExpression(State *state) {
   }
   state->parse_state = copy;
 
+  // typeid(type)
+  if (ParseTwoCharToken(state, "ti") && ParseType(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // typeid(expression)
+  if (ParseTwoCharToken(state, "te") && ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
   // sizeof type
   if (ParseTwoCharToken(state, "st") && ParseType(state)) {
     return true;
   }
   state->parse_state = copy;
 
+  // alignof(type)
+  if (ParseTwoCharToken(state, "at") && ParseType(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // alignof(expression), a GNU extension
+  if (ParseTwoCharToken(state, "az") && ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // noexcept(expression) appearing as an expression in a dependent signature
+  if (ParseTwoCharToken(state, "nx") && ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // sizeof...(pack)
+  //
+  // <expression> ::= sZ <template-param>
+  //              ::= sZ <function-param>
+  if (ParseTwoCharToken(state, "sZ") &&
+      (ParseFunctionParam(state) || ParseTemplateParam(state))) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // sizeof...(pack) captured from an alias template
+  //
+  // <expression> ::= sP <template-arg>* E
+  if (ParseTwoCharToken(state, "sP") && ZeroOrMore(ParseTemplateArg, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // Unary folds (... op pack) and (pack op ...).
+  //
+  // <expression> ::= fl <binary operator-name> <expression>
+  //              ::= fr <binary operator-name> <expression>
+  if ((ParseTwoCharToken(state, "fl") || ParseTwoCharToken(state, "fr")) &&
+      ParseOperatorName(state, nullptr) && ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // Binary folds (init op ... op pack) and (pack op ... op init).
+  //
+  // <expression> ::= fL <binary operator-name> <expression> <expression>
+  //              ::= fR <binary operator-name> <expression> <expression>
+  if ((ParseTwoCharToken(state, "fL") || ParseTwoCharToken(state, "fR")) &&
+      ParseOperatorName(state, nullptr) && ParseExpression(state) &&
+      ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // tw <expression>: throw e
+  if (ParseTwoCharToken(state, "tw") && ParseExpression(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // tr: throw (rethrows an exception from the handler that caught it)
+  if (ParseTwoCharToken(state, "tr")) return true;
+
   // Object and pointer member access expressions.
+  //
+  // <expression> ::= (dt | pt) <expression> <unresolved-name>
   if ((ParseTwoCharToken(state, "dt") || ParseTwoCharToken(state, "pt")) &&
-      ParseExpression(state) && ParseType(state)) {
+      ParseExpression(state) && ParseUnresolvedName(state)) {
     return true;
   }
   state->parse_state = copy;
@@ -1774,9 +2541,61 @@ static bool ParseExpression(State *state) {
   }
   state->parse_state = copy;
 
+  // Vendor extended expressions
+  if (ParseOneCharToken(state, 'u') && ParseSourceName(state) &&
+      ZeroOrMore(ParseTemplateArg, state) && ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // <expression> ::= rq <requirement>+ E
+  //
+  // https://github.com/itanium-cxx-abi/cxx-abi/issues/24
+  if (ParseTwoCharToken(state, "rq") && OneOrMore(ParseRequirement, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  // <expression> ::= rQ <bare-function-type> _ <requirement>+ E
+  //
+  // https://github.com/itanium-cxx-abi/cxx-abi/issues/24
+  if (ParseTwoCharToken(state, "rQ") && ParseBareFunctionType(state) &&
+      ParseOneCharToken(state, '_') && OneOrMore(ParseRequirement, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
   return ParseUnresolvedName(state);
 }
 
+// <initializer> ::= pi <expression>* E
+//               ::= il <braced-expression>* E
+//
+// The il ... E form is not in the ABI spec but is seen in practice for
+// braced-init-lists in new-expressions, which are standard syntax from C++11
+// on.
+static bool ParseInitializer(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+
+  if (ParseTwoCharToken(state, "pi") && ZeroOrMore(ParseExpression, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+
+  if (ParseTwoCharToken(state, "il") &&
+      ZeroOrMore(ParseBracedExpression, state) &&
+      ParseOneCharToken(state, 'E')) {
+    return true;
+  }
+  state->parse_state = copy;
+  return false;
+}
+
 // <expr-primary> ::= L <type> <(value) number> E
 //                ::= L <type> <(value) float> E
 //                ::= L <mangled-name> E
@@ -1819,10 +2638,35 @@ static bool ParseExprPrimary(State *state) {
     return false;
   }
 
-  // The merged cast production.
-  if (ParseOneCharToken(state, 'L') && ParseType(state) &&
-      ParseExprCastValue(state)) {
-    return true;
+  if (ParseOneCharToken(state, 'L')) {
+    // There are two special cases in which a literal may or must contain a type
+    // without a value.  The first is that both LDnE and LDn0E are valid
+    // encodings of nullptr, used in different situations.  Recognize LDnE here,
+    // leaving LDn0E to be recognized by the general logic afterward.
+    if (ParseThreeCharToken(state, "DnE")) return true;
+
+    // The second special case is a string literal, currently mangled in C++98
+    // style as LA<length + 1>_KcE.  This is inadequate to support C++11 and
+    // later versions, and the discussion of this problem has not converged.
+    //
+    // https://github.com/itanium-cxx-abi/cxx-abi/issues/64
+    //
+    // For now the bare-type mangling is what's used in practice, so we
+    // recognize this form and only this form if an array type appears here.
+    // Someday we'll probably have to accept a new form of value mangling in
+    // LA...E constructs.  (Note also that C++20 allows a wide range of
+    // class-type objects as template arguments, so someday their values will be
+    // mangled and we'll have to recognize them here too.)
+    if (RemainingInput(state)[0] == 'A' /* an array type follows */) {
+      if (ParseType(state) && ParseOneCharToken(state, 'E')) return true;
+      state->parse_state = copy;
+      return false;
+    }
+
+    // The merged cast production.
+    if (ParseType(state) && ParseExprCastValueAndTrailingE(state)) {
+      return true;
+    }
   }
   state->parse_state = copy;
 
@@ -1836,7 +2680,7 @@ static bool ParseExprPrimary(State *state) {
 }
 
 // <number> or <float>, followed by 'E', as described above ParseExprPrimary.
-static bool ParseExprCastValue(State *state) {
+static bool ParseExprCastValueAndTrailingE(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   // We have to be able to backtrack after accepting a number because we could
@@ -1848,39 +2692,148 @@ static bool ParseExprCastValue(State *state) {
   }
   state->parse_state = copy;
 
-  if (ParseFloatNumber(state) && ParseOneCharToken(state, 'E')) {
+  if (ParseFloatNumber(state)) {
+    // <float> for ordinary floating-point types
+    if (ParseOneCharToken(state, 'E')) return true;
+
+    // <float> _ <float> for complex floating-point types
+    if (ParseOneCharToken(state, '_') && ParseFloatNumber(state) &&
+        ParseOneCharToken(state, 'E')) {
+      return true;
+    }
+  }
+  state->parse_state = copy;
+
+  return false;
+}
+
+// Parses `Q <requires-clause expr>`.
+// If parsing fails, applies backtracking to `state`.
+//
+// This function covers two symbols instead of one for convenience,
+// because in LLVM's Itanium ABI mangling grammar, <requires-clause expr>
+// always appears after Q.
+//
+// Does not emit the parsed `requires` clause to simplify the implementation.
+// In other words, these two functions' mangled names will demangle identically:
+//
+// template <typename T>
+// int foo(T) requires IsIntegral<T>;
+//
+// vs.
+//
+// template <typename T>
+// int foo(T);
+static bool ParseQRequiresClauseExpr(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+  DisableAppend(state);
+
+  // <requires-clause expr> is just an <expression>: http://shortn/_9E1Ul0rIM8
+  if (ParseOneCharToken(state, 'Q') && ParseExpression(state)) {
+    RestoreAppend(state, copy.append);
+    return true;
+  }
+
+  // also restores append
+  state->parse_state = copy;
+  return false;
+}
+
+// <requirement> ::= X <expression> [N] [R <type-constraint>]
+// <requirement> ::= T <type>
+// <requirement> ::= Q <constraint-expression>
+//
+// <constraint-expression> ::= <expression>
+//
+// https://github.com/itanium-cxx-abi/cxx-abi/issues/24
+static bool ParseRequirement(State *state) {
+  ComplexityGuard guard(state);
+  if (guard.IsTooComplex()) return false;
+
+  ParseState copy = state->parse_state;
+
+  if (ParseOneCharToken(state, 'X') && ParseExpression(state) &&
+      Optional(ParseOneCharToken(state, 'N')) &&
+      // This logic backtracks cleanly if we eat an R but a valid type doesn't
+      // follow it.
+      (!ParseOneCharToken(state, 'R') || ParseTypeConstraint(state))) {
     return true;
   }
   state->parse_state = copy;
 
+  if (ParseOneCharToken(state, 'T') && ParseType(state)) return true;
+  state->parse_state = copy;
+
+  if (ParseOneCharToken(state, 'Q') && ParseExpression(state)) return true;
+  state->parse_state = copy;
+
   return false;
 }
 
+// <type-constraint> ::= <name>
+static bool ParseTypeConstraint(State *state) {
+  return ParseName(state);
+}
+
 // <local-name> ::= Z <(function) encoding> E <(entity) name> [<discriminator>]
 //              ::= Z <(function) encoding> E s [<discriminator>]
+//              ::= Z <(function) encoding> E d [<(parameter) number>] _ <name>
 //
 // Parsing a common prefix of these two productions together avoids an
 // exponential blowup of backtracking.  Parse like:
 //   <local-name> := Z <encoding> E <local-name-suffix>
 //   <local-name-suffix> ::= s [<discriminator>]
+//                       ::= d [<(parameter) number>] _ <name>
 //                       ::= <name> [<discriminator>]
 
 static bool ParseLocalNameSuffix(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
+  ParseState copy = state->parse_state;
+
+  // <local-name-suffix> ::= d [<(parameter) number>] _ <name>
+  if (ParseOneCharToken(state, 'd') &&
+      (IsDigit(RemainingInput(state)[0]) || RemainingInput(state)[0] == '_')) {
+    int number = -1;
+    Optional(ParseNumber(state, &number));
+    if (number < -1 || number > 2147483645) {
+      // Work around overflow cases.  We do not expect these outside of a fuzzer
+      // or other source of adversarial input.  If we do detect overflow here,
+      // we'll print {default arg#1}.
+      number = -1;
+    }
+    number += 2;
+
+    // The ::{default arg#1}:: infix must be rendered before the lambda itself,
+    // so print this before parsing the rest of the <local-name-suffix>.
+    MaybeAppend(state, "::{default arg#");
+    MaybeAppendDecimal(state, number);
+    MaybeAppend(state, "}::");
+    if (ParseOneCharToken(state, '_') && ParseName(state)) return true;
+
+    // On late parse failure, roll back not only the input but also the output,
+    // whose trailing NUL was overwritten.
+    state->parse_state = copy;
+    if (state->parse_state.append) {
+      state->out[state->parse_state.out_cur_idx] = '\0';
+    }
+    return false;
+  }
+  state->parse_state = copy;
 
+  // <local-name-suffix> ::= <name> [<discriminator>]
   if (MaybeAppend(state, "::") && ParseName(state) &&
       Optional(ParseDiscriminator(state))) {
     return true;
   }
-
-  // Since we're not going to overwrite the above "::" by re-parsing the
-  // <encoding> (whose trailing '\0' byte was in the byte now holding the
-  // first ':'), we have to rollback the "::" if the <name> parse failed.
+  state->parse_state = copy;
   if (state->parse_state.append) {
-    state->out[state->parse_state.out_cur_idx - 2] = '\0';
+    state->out[state->parse_state.out_cur_idx] = '\0';
   }
 
+  // <local-name-suffix> ::= s [<discriminator>]
   return ParseOneCharToken(state, 's') && Optional(ParseDiscriminator(state));
 }
 
@@ -1896,12 +2849,22 @@ static bool ParseLocalName(State *state) {
   return false;
 }
 
-// <discriminator> := _ <(non-negative) number>
+// <discriminator> := _ <digit>
+//                 := __ <number (>= 10)> _
 static bool ParseDiscriminator(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   ParseState copy = state->parse_state;
-  if (ParseOneCharToken(state, '_') && ParseNumber(state, nullptr)) {
+
+  // Both forms start with _ so parse that first.
+  if (!ParseOneCharToken(state, '_')) return false;
+
+  // <digit>
+  if (ParseDigit(state, nullptr)) return true;
+
+  // _ <number> _
+  if (ParseOneCharToken(state, '_') && ParseNumber(state, nullptr) &&
+      ParseOneCharToken(state, '_')) {
     return true;
   }
   state->parse_state = copy;
@@ -1947,6 +2910,7 @@ static bool ParseSubstitution(State *state, bool accept_std) {
           MaybeAppend(state, p->real_name);
         }
         ++state->parse_state.mangled_idx;
+        UpdateHighWaterMark(state);
         return true;
       }
     }
@@ -1972,10 +2936,13 @@ static bool ParseTopLevelMangledName(State *state) {
         MaybeAppend(state, RemainingInput(state));
         return true;
       }
+      ReportHighWaterMark(state);
       return false;  // Unconsumed suffix.
     }
     return true;
   }
+
+  ReportHighWaterMark(state);
   return false;
 }
 
@@ -1985,6 +2952,10 @@ static bool Overflowed(const State *state) {
 
 // The demangler entry point.
 bool Demangle(const char* mangled, char* out, size_t out_size) {
+  if (mangled[0] == '_' && mangled[1] == 'R') {
+    return DemangleRustSymbolEncoding(mangled, out, out_size);
+  }
+
   State state;
   InitState(&state, mangled, out, out_size);
   return ParseTopLevelMangledName(&state) && !Overflowed(&state) &&
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.h
index 6acfee2c50..a1166f9e7c 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle.h
@@ -56,6 +56,9 @@ namespace debugging_internal {
 //
 // See the unit test for more examples.
 //
+// Demangle also recognizes Rust mangled names by delegating the parsing of
+// anything that starts with _R to DemangleRustSymbolEncoding (demangle_rust.h).
+//
 // Note: we might want to write demanglers for ABIs other than Itanium
 // C++ ABI in the future.
 bool Demangle(const char* mangled, char* out, size_t out_size);
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle_rust.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle_rust.cc
new file mode 100644
index 0000000000..086e1457f9
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle_rust.cc
@@ -0,0 +1,925 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "y_absl/debugging/internal/demangle_rust.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <limits>
+
+#include "y_absl/base/attributes.h"
+#include "y_absl/base/config.h"
+#include "y_absl/debugging/internal/decode_rust_punycode.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+namespace {
+
+// Same step limit as the C++ demangler in demangle.cc uses.
+constexpr int kMaxReturns = 1 << 17;
+
+bool IsDigit(char c) { return '0' <= c && c <= '9'; }
+bool IsLower(char c) { return 'a' <= c && c <= 'z'; }
+bool IsUpper(char c) { return 'A' <= c && c <= 'Z'; }
+bool IsAlpha(char c) { return IsLower(c) || IsUpper(c); }
+bool IsIdentifierChar(char c) { return IsAlpha(c) || IsDigit(c) || c == '_'; }
+bool IsLowerHexDigit(char c) { return IsDigit(c) || ('a' <= c && c <= 'f'); }
+
+const char* BasicTypeName(char c) {
+  switch (c) {
+    case 'a': return "i8";
+    case 'b': return "bool";
+    case 'c': return "char";
+    case 'd': return "f64";
+    case 'e': return "str";
+    case 'f': return "f32";
+    case 'h': return "u8";
+    case 'i': return "isize";
+    case 'j': return "usize";
+    case 'l': return "i32";
+    case 'm': return "u32";
+    case 'n': return "i128";
+    case 'o': return "u128";
+    case 'p': return "_";
+    case 's': return "i16";
+    case 't': return "u16";
+    case 'u': return "()";
+    case 'v': return "...";
+    case 'x': return "i64";
+    case 'y': return "u64";
+    case 'z': return "!";
+  }
+  return nullptr;
+}
+
+// Parser for Rust symbol mangling v0, whose grammar is defined here:
+//
+// https://doc.rust-lang.org/rustc/symbol-mangling/v0.html#symbol-grammar-summary
+class RustSymbolParser {
+ public:
+  // Prepares to demangle the given encoding, a Rust symbol name starting with
+  // _R, into the output buffer [out, out_end).  The caller is expected to
+  // continue by calling the new object's Parse function.
+  RustSymbolParser(const char* encoding, char* out, char* const out_end)
+      : encoding_(encoding), out_(out), out_end_(out_end) {
+    if (out_ != out_end_) *out_ = '\0';
+  }
+
+  // Parses the constructor's encoding argument, writing output into the range
+  // [out, out_end).  Returns true on success and false for input whose
+  // structure was not recognized or exceeded implementation limits, such as by
+  // nesting structures too deep.  In either case *this should not be used
+  // again.
+  Y_ABSL_MUST_USE_RESULT bool Parse() && {
+    // Recursively parses the grammar production named by callee, then resumes
+    // execution at the next statement.
+    //
+    // Recursive-descent parsing is a beautifully readable translation of a
+    // grammar, but it risks stack overflow if implemented by naive recursion on
+    // the C++ call stack.  So we simulate recursion by goto and switch instead,
+    // keeping a bounded stack of "return addresses" in the recursion_stack_
+    // member.
+    //
+    // The callee argument is a statement label.  We goto that label after
+    // saving the "return address" on recursion_stack_.  The next continue
+    // statement in the for loop below "returns" from this "call".
+    //
+    // The caller argument names the return point.  Each value of caller must
+    // appear in only one Y_ABSL_DEMANGLER_RECURSE call and be listed in the
+    // definition of enum ReturnAddress.  The switch implements the control
+    // transfer from the end of a "called" subroutine back to the statement
+    // after the "call".
+    //
+    // Note that not all the grammar productions have to be packed into the
+    // switch, but only those which appear in a cycle in the grammar.  Anything
+    // acyclic can be written as ordinary functions and function calls, e.g.,
+    // ParseIdentifier.
+#define Y_ABSL_DEMANGLER_RECURSE(callee, caller) \
+    do { \
+      if (recursion_depth_ == kStackSize) return false; \
+      /* The next continue will switch on this saved value ... */ \
+      recursion_stack_[recursion_depth_++] = caller; \
+      goto callee; \
+      /* ... and will land here, resuming the suspended code. */ \
+      case caller: {} \
+    } while (0)
+
+    // Parse the encoding, counting completed recursive calls to guard against
+    // excessively complex input and infinite-loop bugs.
+    int iter = 0;
+    goto whole_encoding;
+    for (; iter < kMaxReturns && recursion_depth_ > 0; ++iter) {
+      // This switch resumes the code path most recently suspended by
+      // Y_ABSL_DEMANGLER_RECURSE.
+      switch (recursion_stack_[--recursion_depth_]) {
+        //
+        // symbol-name ->
+        // _R decimal-number? path instantiating-crate? vendor-specific-suffix?
+        whole_encoding:
+          if (!Eat('_') || !Eat('R')) return false;
+          // decimal-number? is always empty today, so proceed to path, which
+          // can't start with a decimal digit.
+          Y_ABSL_DEMANGLER_RECURSE(path, kInstantiatingCrate);
+          if (IsAlpha(Peek())) {
+            ++silence_depth_;  // Print nothing more from here on.
+            Y_ABSL_DEMANGLER_RECURSE(path, kVendorSpecificSuffix);
+          }
+          switch (Take()) {
+            case '.': case '$': case '\0': return true;
+          }
+          return false;  // unexpected trailing content
+
+        // path -> crate-root | inherent-impl | trait-impl | trait-definition |
+        //         nested-path | generic-args | backref
+        //
+        // Note that Y_ABSL_DEMANGLER_RECURSE does not work inside a nested switch
+        // (which would hide the generated case label).  Thus we jump out of the
+        // inner switch with gotos before performing any fake recursion.
+        path:
+          switch (Take()) {
+            case 'C': goto crate_root;
+            case 'M': goto inherent_impl;
+            case 'X': goto trait_impl;
+            case 'Y': goto trait_definition;
+            case 'N': goto nested_path;
+            case 'I': goto generic_args;
+            case 'B': goto path_backref;
+            default: return false;
+          }
+
+        // crate-root -> C identifier (C consumed above)
+        crate_root:
+          if (!ParseIdentifier()) return false;
+          continue;
+
+        // inherent-impl -> M impl-path type (M already consumed)
+        inherent_impl:
+          if (!Emit("<")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(impl_path, kInherentImplType);
+          Y_ABSL_DEMANGLER_RECURSE(type, kInherentImplEnding);
+          if (!Emit(">")) return false;
+          continue;
+
+        // trait-impl -> X impl-path type path (X already consumed)
+        trait_impl:
+          if (!Emit("<")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(impl_path, kTraitImplType);
+          Y_ABSL_DEMANGLER_RECURSE(type, kTraitImplInfix);
+          if (!Emit(" as ")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(path, kTraitImplEnding);
+          if (!Emit(">")) return false;
+          continue;
+
+        // impl-path -> disambiguator? path (but never print it!)
+        impl_path:
+          ++silence_depth_;
+          {
+            int ignored_disambiguator;
+            if (!ParseDisambiguator(ignored_disambiguator)) return false;
+          }
+          Y_ABSL_DEMANGLER_RECURSE(path, kImplPathEnding);
+          --silence_depth_;
+          continue;
+
+        // trait-definition -> Y type path (Y already consumed)
+        trait_definition:
+          if (!Emit("<")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(type, kTraitDefinitionInfix);
+          if (!Emit(" as ")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(path, kTraitDefinitionEnding);
+          if (!Emit(">")) return false;
+          continue;
+
+        // nested-path -> N namespace path identifier (N already consumed)
+        // namespace -> lower | upper
+        nested_path:
+          // Uppercase namespaces must be saved on a stack so we can print
+          // ::{closure#0} or ::{shim:vtable#0} or ::{X:name#0} as needed.
+          if (IsUpper(Peek())) {
+            if (!PushNamespace(Take())) return false;
+            Y_ABSL_DEMANGLER_RECURSE(path, kIdentifierInUppercaseNamespace);
+            if (!Emit("::")) return false;
+            if (!ParseIdentifier(PopNamespace())) return false;
+            continue;
+          }
+
+          // Lowercase namespaces, however, are never represented in the output;
+          // they all emit just ::name.
+          if (IsLower(Take())) {
+            Y_ABSL_DEMANGLER_RECURSE(path, kIdentifierInLowercaseNamespace);
+            if (!Emit("::")) return false;
+            if (!ParseIdentifier()) return false;
+            continue;
+          }
+
+          // Neither upper or lower
+          return false;
+
+        // type -> basic-type | array-type | slice-type | tuple-type |
+        //         ref-type | mut-ref-type | const-ptr-type | mut-ptr-type |
+        //         fn-type | dyn-trait-type | path | backref
+        //
+        // We use ifs instead of switch (Take()) because the default case jumps
+        // to path, which will need to see the first character not yet Taken
+        // from the input.  Because we do not use a nested switch here,
+        // Y_ABSL_DEMANGLER_RECURSE works fine in the 'S' case.
+        type:
+          if (IsLower(Peek())) {
+            const char* type_name = BasicTypeName(Take());
+            if (type_name == nullptr || !Emit(type_name)) return false;
+            continue;
+          }
+          if (Eat('A')) {
+            // array-type = A type const
+            if (!Emit("[")) return false;
+            Y_ABSL_DEMANGLER_RECURSE(type, kArraySize);
+            if (!Emit("; ")) return false;
+            Y_ABSL_DEMANGLER_RECURSE(constant, kFinishArray);
+            if (!Emit("]")) return false;
+            continue;
+          }
+          if (Eat('S')) {
+            if (!Emit("[")) return false;
+            Y_ABSL_DEMANGLER_RECURSE(type, kSliceEnding);
+            if (!Emit("]")) return false;
+            continue;
+          }
+          if (Eat('T')) goto tuple_type;
+          if (Eat('R')) {
+            if (!Emit("&")) return false;
+            if (!ParseOptionalLifetime()) return false;
+            goto type;
+          }
+          if (Eat('Q')) {
+            if (!Emit("&mut ")) return false;
+            if (!ParseOptionalLifetime()) return false;
+            goto type;
+          }
+          if (Eat('P')) {
+            if (!Emit("*const ")) return false;
+            goto type;
+          }
+          if (Eat('O')) {
+            if (!Emit("*mut ")) return false;
+            goto type;
+          }
+          if (Eat('F')) goto fn_type;
+          if (Eat('D')) goto dyn_trait_type;
+          if (Eat('B')) goto type_backref;
+          goto path;
+
+        // tuple-type -> T type* E (T already consumed)
+        tuple_type:
+          if (!Emit("(")) return false;
+
+          // The toolchain should call the unit type u instead of TE, but the
+          // grammar and other demanglers also recognize TE, so we do too.
+          if (Eat('E')) {
+            if (!Emit(")")) return false;
+            continue;
+          }
+
+          // A tuple with one element is rendered (type,) instead of (type).
+          Y_ABSL_DEMANGLER_RECURSE(type, kAfterFirstTupleElement);
+          if (Eat('E')) {
+            if (!Emit(",)")) return false;
+            continue;
+          }
+
+          // A tuple with two elements is of course (x, y).
+          if (!Emit(", ")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(type, kAfterSecondTupleElement);
+          if (Eat('E')) {
+            if (!Emit(")")) return false;
+            continue;
+          }
+
+          // And (x, y, z) for three elements.
+          if (!Emit(", ")) return false;
+          Y_ABSL_DEMANGLER_RECURSE(type, kAfterThirdTupleElement);
+          if (Eat('E')) {
+            if (!Emit(")")) return false;
+            continue;
+          }
+
+          // For longer tuples we write (x, y, z, ...), printing none of the
+          // content of the fourth and later types.  Thus we avoid exhausting
+          // output buffers and human readers' patience when some library has a
+          // long tuple as an implementation detail, without having to
+          // completely obfuscate all tuples.
+          if (!Emit(", ...)")) return false;
+          ++silence_depth_;
+          while (!Eat('E')) {
+            Y_ABSL_DEMANGLER_RECURSE(type, kAfterSubsequentTupleElement);
+          }
+          --silence_depth_;
+          continue;
+
+        // fn-type -> F fn-sig (F already consumed)
+        // fn-sig -> binder? U? (K abi)? type* E type
+        // abi -> C | undisambiguated-identifier
+        //
+        // We follow the C++ demangler in suppressing details of function
+        // signatures.  Every function type is rendered "fn...".
+        fn_type:
+          if (!Emit("fn...")) return false;
+          ++silence_depth_;
+          if (!ParseOptionalBinder()) return false;
+          (void)Eat('U');
+          if (Eat('K')) {
+            if (!Eat('C') && !ParseUndisambiguatedIdentifier()) return false;
+          }
+          while (!Eat('E')) {
+            Y_ABSL_DEMANGLER_RECURSE(type, kContinueParameterList);
+          }
+          Y_ABSL_DEMANGLER_RECURSE(type, kFinishFn);
+          --silence_depth_;
+          continue;
+
+        // dyn-trait-type -> D dyn-bounds lifetime (D already consumed)
+        // dyn-bounds -> binder? dyn-trait* E
+        //
+        // The grammar strangely allows an empty trait list, even though the
+        // compiler should never output one.  We follow existing demanglers in
+        // rendering DEL_ as "dyn ".
+        //
+        // Because auto traits lengthen a type name considerably without
+        // providing much value to a search for related source code, it would be
+        // desirable to abbreviate
+        //     dyn main::Trait + std::marker::Copy + std::marker::Send
+        // to
+        //     dyn main::Trait + ...,
+        // eliding the auto traits.  But it is difficult to do so correctly, in
+        // part because there is no guarantee that the mangling will list the
+        // main trait first.  So we just print all the traits in their order of
+        // appearance in the mangled name.
+        dyn_trait_type:
+          if (!Emit("dyn ")) return false;
+          if (!ParseOptionalBinder()) return false;
+          if (!Eat('E')) {
+            Y_ABSL_DEMANGLER_RECURSE(dyn_trait, kBeginAutoTraits);
+            while (!Eat('E')) {
+              if (!Emit(" + ")) return false;
+              Y_ABSL_DEMANGLER_RECURSE(dyn_trait, kContinueAutoTraits);
+            }
+          }
+          if (!ParseRequiredLifetime()) return false;
+          continue;
+
+        // dyn-trait -> path dyn-trait-assoc-binding*
+        // dyn-trait-assoc-binding -> p undisambiguated-identifier type
+        //
+        // We render nonempty binding lists as <>, omitting their contents as
+        // for generic-args.
+        dyn_trait:
+          Y_ABSL_DEMANGLER_RECURSE(path, kContinueDynTrait);
+          if (Peek() == 'p') {
+            if (!Emit("<>")) return false;
+            ++silence_depth_;
+            while (Eat('p')) {
+              if (!ParseUndisambiguatedIdentifier()) return false;
+              Y_ABSL_DEMANGLER_RECURSE(type, kContinueAssocBinding);
+            }
+            --silence_depth_;
+          }
+          continue;
+
+        // const -> type const-data | p | backref
+        //
+        // const is a C++ keyword, so we use the label `constant` instead.
+        constant:
+          if (Eat('B')) goto const_backref;
+          if (Eat('p')) {
+            if (!Emit("_")) return false;
+            continue;
+          }
+
+          // Scan the type without printing it.
+          //
+          // The Rust language restricts the type of a const generic argument
+          // much more than the mangling grammar does.  We do not enforce this.
+          //
+          // We also do not bother printing false, true, 'A', and '\u{abcd}' for
+          // the types bool and char.  Because we do not print generic-args
+          // contents, we expect to print constants only in array sizes, and
+          // those should not be bool or char.
+          ++silence_depth_;
+          Y_ABSL_DEMANGLER_RECURSE(type, kConstData);
+          --silence_depth_;
+
+          // const-data -> n? hex-digit* _
+          //
+          // Although the grammar doesn't say this, existing demanglers expect
+          // that zero is 0, not an empty digit sequence, and no nonzero value
+          // may have leading zero digits.  Also n0_ is accepted and printed as
+          // -0, though a toolchain will probably never write that encoding.
+          if (Eat('n') && !EmitChar('-')) return false;
+          if (!Emit("0x")) return false;
+          if (Eat('0')) {
+            if (!EmitChar('0')) return false;
+            if (!Eat('_')) return false;
+            continue;
+          }
+          while (IsLowerHexDigit(Peek())) {
+            if (!EmitChar(Take())) return false;
+          }
+          if (!Eat('_')) return false;
+          continue;
+
+        // generic-args -> I path generic-arg* E (I already consumed)
+        //
+        // We follow the C++ demangler in omitting all the arguments from the
+        // output, printing only the list opening and closing tokens.
+        generic_args:
+          Y_ABSL_DEMANGLER_RECURSE(path, kBeginGenericArgList);
+          if (!Emit("::<>")) return false;
+          ++silence_depth_;
+          while (!Eat('E')) {
+            Y_ABSL_DEMANGLER_RECURSE(generic_arg, kContinueGenericArgList);
+          }
+          --silence_depth_;
+          continue;
+
+        // generic-arg -> lifetime | type | K const
+        generic_arg:
+          if (Peek() == 'L') {
+            if (!ParseOptionalLifetime()) return false;
+            continue;
+          }
+          if (Eat('K')) goto constant;
+          goto type;
+
+        // backref -> B base-62-number (B already consumed)
+        //
+        // The BeginBackref call parses and range-checks the base-62-number.  We
+        // always do that much.
+        //
+        // The recursive call parses and prints what the backref points at.  We
+        // save CPU and stack by skipping this work if the output would be
+        // suppressed anyway.
+        path_backref:
+          if (!BeginBackref()) return false;
+          if (silence_depth_ == 0) {
+            Y_ABSL_DEMANGLER_RECURSE(path, kPathBackrefEnding);
+          }
+          EndBackref();
+          continue;
+
+        // This represents the same backref production as in path_backref but
+        // parses the target as a type instead of a path.
+        type_backref:
+          if (!BeginBackref()) return false;
+          if (silence_depth_ == 0) {
+            Y_ABSL_DEMANGLER_RECURSE(type, kTypeBackrefEnding);
+          }
+          EndBackref();
+          continue;
+
+        const_backref:
+          if (!BeginBackref()) return false;
+          if (silence_depth_ == 0) {
+            Y_ABSL_DEMANGLER_RECURSE(constant, kConstantBackrefEnding);
+          }
+          EndBackref();
+          continue;
+      }
+    }
+
+    return false;  // hit iteration limit or a bug in our stack handling
+  }
+
+ private:
+  // Enumerates resumption points for Y_ABSL_DEMANGLER_RECURSE calls.
+  enum ReturnAddress : uint8_t {
+    kInstantiatingCrate,
+    kVendorSpecificSuffix,
+    kIdentifierInUppercaseNamespace,
+    kIdentifierInLowercaseNamespace,
+    kInherentImplType,
+    kInherentImplEnding,
+    kTraitImplType,
+    kTraitImplInfix,
+    kTraitImplEnding,
+    kImplPathEnding,
+    kTraitDefinitionInfix,
+    kTraitDefinitionEnding,
+    kArraySize,
+    kFinishArray,
+    kSliceEnding,
+    kAfterFirstTupleElement,
+    kAfterSecondTupleElement,
+    kAfterThirdTupleElement,
+    kAfterSubsequentTupleElement,
+    kContinueParameterList,
+    kFinishFn,
+    kBeginAutoTraits,
+    kContinueAutoTraits,
+    kContinueDynTrait,
+    kContinueAssocBinding,
+    kConstData,
+    kBeginGenericArgList,
+    kContinueGenericArgList,
+    kPathBackrefEnding,
+    kTypeBackrefEnding,
+    kConstantBackrefEnding,
+  };
+
+  // Element counts for the stack arrays.  Larger stack sizes accommodate more
+  // deeply nested names at the cost of a larger footprint on the C++ call
+  // stack.
+  enum {
+    // Maximum recursive calls outstanding at one time.
+    kStackSize = 256,
+
+    // Maximum N<uppercase> nested-paths open at once.  We do not expect
+    // closures inside closures inside closures as much as functions inside
+    // modules inside other modules, so we can use a smaller array here.
+    kNamespaceStackSize = 64,
+
+    // Maximum number of nested backrefs.  We can keep this stack pretty small
+    // because we do not follow backrefs inside generic-args or other contexts
+    // that suppress printing, so deep stacking is unlikely in practice.
+    kPositionStackSize = 16,
+  };
+
+  // Returns the next input character without consuming it.
+  char Peek() const { return encoding_[pos_]; }
+
+  // Consumes and returns the next input character.
+  char Take() { return encoding_[pos_++]; }
+
+  // If the next input character is the given character, consumes it and returns
+  // true; otherwise returns false without consuming a character.
+  Y_ABSL_MUST_USE_RESULT bool Eat(char want) {
+    if (encoding_[pos_] != want) return false;
+    ++pos_;
+    return true;
+  }
+
+  // Provided there is enough remaining output space, appends c to the output,
+  // writing a fresh NUL terminator afterward, and returns true.  Returns false
+  // if the output buffer had less than two bytes free.
+  Y_ABSL_MUST_USE_RESULT bool EmitChar(char c) {
+    if (silence_depth_ > 0) return true;
+    if (out_end_ - out_ < 2) return false;
+    *out_++ = c;
+    *out_ = '\0';
+    return true;
+  }
+
+  // Provided there is enough remaining output space, appends the C string token
+  // to the output, followed by a NUL character, and returns true.  Returns
+  // false if not everything fit into the output buffer.
+  Y_ABSL_MUST_USE_RESULT bool Emit(const char* token) {
+    if (silence_depth_ > 0) return true;
+    const size_t token_length = std::strlen(token);
+    const size_t bytes_to_copy = token_length + 1;  // token and final NUL
+    if (static_cast<size_t>(out_end_ - out_) < bytes_to_copy) return false;
+    std::memcpy(out_, token, bytes_to_copy);
+    out_ += token_length;
+    return true;
+  }
+
+  // Provided there is enough remaining output space, appends the decimal form
+  // of disambiguator (if it's nonnegative) or "?" (if it's negative) to the
+  // output, followed by a NUL character, and returns true.  Returns false if
+  // not everything fit into the output buffer.
+  Y_ABSL_MUST_USE_RESULT bool EmitDisambiguator(int disambiguator) {
+    if (disambiguator < 0) return EmitChar('?');  // parsed but too large
+    if (disambiguator == 0) return EmitChar('0');
+    // Convert disambiguator to decimal text.  Three digits per byte is enough
+    // because 999 > 256.  The bound will remain correct even if future
+    // maintenance changes the type of the disambiguator variable.
+    char digits[3 * sizeof(disambiguator)] = {};
+    size_t leading_digit_index = sizeof(digits) - 1;
+    for (; disambiguator > 0; disambiguator /= 10) {
+      digits[--leading_digit_index] =
+          static_cast<char>('0' + disambiguator % 10);
+    }
+    return Emit(digits + leading_digit_index);
+  }
+
+  // Consumes an optional disambiguator (s123_) from the input.
+  //
+  // On success returns true and fills value with the encoded value if it was
+  // not too big, otherwise with -1.  If the optional disambiguator was omitted,
+  // value is 0.  On parse failure returns false and sets value to -1.
+  Y_ABSL_MUST_USE_RESULT bool ParseDisambiguator(int& value) {
+    value = -1;
+
+    // disambiguator = s base-62-number
+    //
+    // Disambiguators are optional.  An omitted disambiguator is zero.
+    if (!Eat('s')) {
+      value = 0;
+      return true;
+    }
+    int base_62_value = 0;
+    if (!ParseBase62Number(base_62_value)) return false;
+    value = base_62_value < 0 ? -1 : base_62_value + 1;
+    return true;
+  }
+
+  // Consumes a base-62 number like _ or 123_ from the input.
+  //
+  // On success returns true and fills value with the encoded value if it was
+  // not too big, otherwise with -1.  On parse failure returns false and sets
+  // value to -1.
+  Y_ABSL_MUST_USE_RESULT bool ParseBase62Number(int& value) {
+    value = -1;
+
+    // base-62-number = (digit | lower | upper)* _
+    //
+    // An empty base-62 digit sequence means 0.
+    if (Eat('_')) {
+      value = 0;
+      return true;
+    }
+
+    // A nonempty digit sequence denotes its base-62 value plus 1.
+    int encoded_number = 0;
+    bool overflowed = false;
+    while (IsAlpha(Peek()) || IsDigit(Peek())) {
+      const char c = Take();
+      if (encoded_number >= std::numeric_limits<int>::max()/62) {
+        // If we are close to overflowing an int, keep parsing but stop updating
+        // encoded_number and remember to return -1 at the end.  The point is to
+        // avoid undefined behavior while parsing crate-root disambiguators,
+        // which are large in practice but not shown in demangling, while
+        // successfully computing closure and shim disambiguators, which are
+        // typically small and are printed out.
+        overflowed = true;
+      } else {
+        int digit;
+        if (IsDigit(c)) {
+          digit = c - '0';
+        } else if (IsLower(c)) {
+          digit = c - 'a' + 10;
+        } else {
+          digit = c - 'A' + 36;
+        }
+        encoded_number = 62 * encoded_number + digit;
+      }
+    }
+
+    if (!Eat('_')) return false;
+    if (!overflowed) value = encoded_number + 1;
+    return true;
+  }
+
+  // Consumes an identifier from the input, returning true on success.
+  //
+  // A nonzero uppercase_namespace specifies the character after the N in a
+  // nested-identifier, e.g., 'C' for a closure, allowing ParseIdentifier to
+  // write out the name with the conventional decoration for that namespace.
+  Y_ABSL_MUST_USE_RESULT bool ParseIdentifier(char uppercase_namespace = '\0') {
+    // identifier -> disambiguator? undisambiguated-identifier
+    int disambiguator = 0;
+    if (!ParseDisambiguator(disambiguator)) return false;
+
+    return ParseUndisambiguatedIdentifier(uppercase_namespace, disambiguator);
+  }
+
+  // Consumes from the input an identifier with no preceding disambiguator,
+  // returning true on success.
+  //
+  // When ParseIdentifier calls this, it passes the N<namespace> character and
+  // disambiguator value so that "{closure#42}" and similar forms can be
+  // rendered correctly.
+  //
+  // At other appearances of undisambiguated-identifier in the grammar, this
+  // treatment is not applicable, and the call site omits both arguments.
+  Y_ABSL_MUST_USE_RESULT bool ParseUndisambiguatedIdentifier(
+      char uppercase_namespace = '\0', int disambiguator = 0) {
+    // undisambiguated-identifier -> u? decimal-number _? bytes
+    const bool is_punycoded = Eat('u');
+    if (!IsDigit(Peek())) return false;
+    int num_bytes = 0;
+    if (!ParseDecimalNumber(num_bytes)) return false;
+    (void)Eat('_');  // optional separator, needed if a digit follows
+    if (is_punycoded) {
+      DecodeRustPunycodeOptions options;
+      options.punycode_begin = &encoding_[pos_];
+      options.punycode_end = &encoding_[pos_] + num_bytes;
+      options.out_begin = out_;
+      options.out_end = out_end_;
+      out_ = DecodeRustPunycode(options);
+      if (out_ == nullptr) return false;
+      pos_ += static_cast<size_t>(num_bytes);
+    }
+
+    // Emit the beginnings of braced forms like {shim:vtable#0}.
+    if (uppercase_namespace != '\0') {
+      switch (uppercase_namespace) {
+        case 'C':
+          if (!Emit("{closure")) return false;
+          break;
+        case 'S':
+          if (!Emit("{shim")) return false;
+          break;
+        default:
+          if (!EmitChar('{') || !EmitChar(uppercase_namespace)) return false;
+          break;
+      }
+      if (num_bytes > 0 && !Emit(":")) return false;
+    }
+
+    // Emit the name itself.
+    if (!is_punycoded) {
+      for (int i = 0; i < num_bytes; ++i) {
+        const char c = Take();
+        if (!IsIdentifierChar(c) &&
+            // The spec gives toolchains the choice of Punycode or raw UTF-8 for
+            // identifiers containing code points above 0x7f, so accept bytes
+            // with the high bit set.
+            (c & 0x80) == 0) {
+          return false;
+        }
+        if (!EmitChar(c)) return false;
+      }
+    }
+
+    // Emit the endings of braced forms, e.g., "#42}".
+    if (uppercase_namespace != '\0') {
+      if (!EmitChar('#')) return false;
+      if (!EmitDisambiguator(disambiguator)) return false;
+      if (!EmitChar('}')) return false;
+    }
+
+    return true;
+  }
+
+  // Consumes a decimal number like 0 or 123 from the input.  On success returns
+  // true and fills value with the encoded value.  If the encoded value is too
+  // large or otherwise unparsable, returns false and sets value to -1.
+  Y_ABSL_MUST_USE_RESULT bool ParseDecimalNumber(int& value) {
+    value = -1;
+    if (!IsDigit(Peek())) return false;
+    int encoded_number = Take() - '0';
+    if (encoded_number == 0) {
+      // Decimal numbers are never encoded with extra leading zeroes.
+      value = 0;
+      return true;
+    }
+    while (IsDigit(Peek()) &&
+           // avoid overflow
+           encoded_number < std::numeric_limits<int>::max()/10) {
+      encoded_number = 10 * encoded_number + (Take() - '0');
+    }
+    if (IsDigit(Peek())) return false;  // too big
+    value = encoded_number;
+    return true;
+  }
+
+  // Consumes a binder of higher-ranked lifetimes if one is present.  On success
+  // returns true and discards the encoded lifetime count.  On parse failure
+  // returns false.
+  Y_ABSL_MUST_USE_RESULT bool ParseOptionalBinder() {
+    // binder -> G base-62-number
+    if (!Eat('G')) return true;
+    int ignored_binding_count;
+    return ParseBase62Number(ignored_binding_count);
+  }
+
+  // Consumes a lifetime if one is present.
+  //
+  // On success returns true and discards the lifetime index.  We do not print
+  // or even range-check lifetimes because they are a finer detail than other
+  // things we omit from output, such as the entire contents of generic-args.
+  //
+  // On parse failure returns false.
+  Y_ABSL_MUST_USE_RESULT bool ParseOptionalLifetime() {
+    // lifetime -> L base-62-number
+    if (!Eat('L')) return true;
+    int ignored_de_bruijn_index;
+    return ParseBase62Number(ignored_de_bruijn_index);
+  }
+
+  // Consumes a lifetime just like ParseOptionalLifetime, but returns false if
+  // there is no lifetime here.
+  Y_ABSL_MUST_USE_RESULT bool ParseRequiredLifetime() {
+    if (Peek() != 'L') return false;
+    return ParseOptionalLifetime();
+  }
+
+  // Pushes ns onto the namespace stack and returns true if the stack is not
+  // full, else returns false.
+  Y_ABSL_MUST_USE_RESULT bool PushNamespace(char ns) {
+    if (namespace_depth_ == kNamespaceStackSize) return false;
+    namespace_stack_[namespace_depth_++] = ns;
+    return true;
+  }
+
+  // Pops the last pushed namespace.  Requires that the namespace stack is not
+  // empty (namespace_depth_ > 0).
+  char PopNamespace() { return namespace_stack_[--namespace_depth_]; }
+
+  // Pushes position onto the position stack and returns true if the stack is
+  // not full, else returns false.
+  Y_ABSL_MUST_USE_RESULT bool PushPosition(int position) {
+    if (position_depth_ == kPositionStackSize) return false;
+    position_stack_[position_depth_++] = position;
+    return true;
+  }
+
+  // Pops the last pushed input position.  Requires that the position stack is
+  // not empty (position_depth_ > 0).
+  int PopPosition() { return position_stack_[--position_depth_]; }
+
+  // Consumes a base-62-number denoting a backref target, pushes the current
+  // input position on the data stack, and sets the input position to the
+  // beginning of the backref target.  Returns true on success.  Returns false
+  // if parsing failed, the stack is exhausted, or the backref target position
+  // is out of range.
+  Y_ABSL_MUST_USE_RESULT bool BeginBackref() {
+    // backref = B base-62-number (B already consumed)
+    //
+    // Reject backrefs that don't parse, overflow int, or don't point backward.
+    // If the offset looks fine, adjust it to account for the _R prefix.
+    int offset = 0;
+    const int offset_of_this_backref =
+        pos_ - 2 /* _R */ - 1 /* B already consumed */;
+    if (!ParseBase62Number(offset) || offset < 0 ||
+        offset >= offset_of_this_backref) {
+      return false;
+    }
+    offset += 2;
+
+    // Save the old position to restore later.
+    if (!PushPosition(pos_)) return false;
+
+    // Move the input position to the backref target.
+    //
+    // Note that we do not check whether the new position points to the
+    // beginning of a construct matching the context in which the backref
+    // appeared.  We just jump to it and see whether nested parsing succeeds.
+    // We therefore accept various wrong manglings, e.g., a type backref
+    // pointing to an 'l' character inside an identifier, which happens to mean
+    // i32 when parsed as a type mangling.  This saves the complexity and RAM
+    // footprint of remembering which offsets began which kinds of
+    // substructures.  Existing demanglers take similar shortcuts.
+    pos_ = offset;
+    return true;
+  }
+
+  // Cleans up after a backref production by restoring the previous input
+  // position from the data stack.
+  void EndBackref() { pos_ = PopPosition(); }
+
+  // The leftmost recursion_depth_ elements of recursion_stack_ contain the
+  // ReturnAddresses pushed by Y_ABSL_DEMANGLER_RECURSE calls not yet completed.
+  ReturnAddress recursion_stack_[kStackSize] = {};
+  int recursion_depth_ = 0;
+
+  // The leftmost namespace_depth_ elements of namespace_stack_ contain the
+  // uppercase namespace identifiers for open nested-paths, e.g., 'C' for a
+  // closure.
+  char namespace_stack_[kNamespaceStackSize] = {};
+  int namespace_depth_ = 0;
+
+  // The leftmost position_depth_ elements of position_stack_ contain the input
+  // positions to return to after fully printing the targets of backrefs.
+  int position_stack_[kPositionStackSize] = {};
+  int position_depth_ = 0;
+
+  // Anything parsed while silence_depth_ > 0 contributes nothing to the
+  // demangled output.  For constructs omitted from the demangling, such as
+  // impl-path and the contents of generic-args, we will increment
+  // silence_depth_ on the way in and decrement silence_depth_ on the way out.
+  int silence_depth_ = 0;
+
+  // Input: encoding_ points to a Rust mangled symbol, and encoding_[pos_] is
+  // the next input character to be scanned.
+  int pos_ = 0;
+  const char* encoding_ = nullptr;
+
+  // Output: *out_ is where the next output character should be written, and
+  // out_end_ points past the last byte of available space.
+  char* out_ = nullptr;
+  char* out_end_ = nullptr;
+};
+
+}  // namespace
+
+bool DemangleRustSymbolEncoding(const char* mangled, char* out,
+                                size_t out_size) {
+  return RustSymbolParser(mangled, out, out + out_size).Parse();
+}
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle_rust.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle_rust.h
new file mode 100644
index 0000000000..70ec90d3b9
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/demangle_rust.h
@@ -0,0 +1,42 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef Y_ABSL_DEBUGGING_INTERNAL_DEMANGLE_RUST_H_
+#define Y_ABSL_DEBUGGING_INTERNAL_DEMANGLE_RUST_H_
+
+#include <cstddef>
+
+#include "y_absl/base/config.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Demangle the Rust encoding `mangled`.  On success, return true and write the
+// demangled symbol name to `out`.  Otherwise, return false, leaving unspecified
+// contents in `out`.  For example, calling DemangleRustSymbolEncoding with
+// `mangled = "_RNvC8my_crate7my_func"` will yield `my_crate::my_func` in `out`,
+// provided `out_size` is large enough for that value and its trailing NUL.
+//
+// DemangleRustSymbolEncoding is async-signal-safe and runs in bounded C++
+// call-stack space.  It is suitable for symbolizing stack traces in a signal
+// handler.
+bool DemangleRustSymbolEncoding(const char* mangled, char* out,
+                                size_t out_size);
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_DEBUGGING_INTERNAL_DEMANGLE_RUST_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.cc
index cead525c93..f9fc638597 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.cc
@@ -20,8 +20,11 @@
 #ifdef Y_ABSL_HAVE_ELF_MEM_IMAGE  // defined in elf_mem_image.h
 
 #include <string.h>
+
 #include <cassert>
 #include <cstddef>
+#include <cstdint>
+
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/raw_logging.h"
 
@@ -86,20 +89,14 @@ ElfMemImage::ElfMemImage(const void *base) {
   Init(base);
 }
 
-int ElfMemImage::GetNumSymbols() const {
-  if (!hash_) {
-    return 0;
-  }
-  // See http://www.caldera.com/developers/gabi/latest/ch5.dynamic.html#hash
-  return static_cast<int>(hash_[1]);
-}
+uint32_t ElfMemImage::GetNumSymbols() const { return num_syms_; }
 
-const ElfW(Sym) *ElfMemImage::GetDynsym(int index) const {
+const ElfW(Sym) * ElfMemImage::GetDynsym(uint32_t index) const {
   Y_ABSL_RAW_CHECK(index < GetNumSymbols(), "index out of range");
   return dynsym_ + index;
 }
 
-const ElfW(Versym) *ElfMemImage::GetVersym(int index) const {
+const ElfW(Versym) *ElfMemImage::GetVersym(uint32_t index) const {
   Y_ABSL_RAW_CHECK(index < GetNumSymbols(), "index out of range");
   return versym_ + index;
 }
@@ -154,7 +151,7 @@ void ElfMemImage::Init(const void *base) {
   dynstr_    = nullptr;
   versym_    = nullptr;
   verdef_    = nullptr;
-  hash_      = nullptr;
+  num_syms_ = 0;
   strsize_   = 0;
   verdefnum_ = 0;
   // Sentinel: PT_LOAD .p_vaddr can't possibly be this.
@@ -219,12 +216,17 @@ void ElfMemImage::Init(const void *base) {
       base_as_char - reinterpret_cast<const char *>(link_base_);
   ElfW(Dyn)* dynamic_entry = reinterpret_cast<ElfW(Dyn)*>(
       static_cast<intptr_t>(dynamic_program_header->p_vaddr) + relocation);
+  uint32_t *sysv_hash = nullptr;
+  uint32_t *gnu_hash = nullptr;
   for (; dynamic_entry->d_tag != DT_NULL; ++dynamic_entry) {
     const auto value =
         static_cast<intptr_t>(dynamic_entry->d_un.d_val) + relocation;
     switch (dynamic_entry->d_tag) {
       case DT_HASH:
-        hash_ = reinterpret_cast<ElfW(Word) *>(value);
+        sysv_hash = reinterpret_cast<uint32_t *>(value);
+        break;
+      case DT_GNU_HASH:
+        gnu_hash = reinterpret_cast<uint32_t *>(value);
         break;
       case DT_SYMTAB:
         dynsym_ = reinterpret_cast<ElfW(Sym) *>(value);
@@ -249,13 +251,38 @@ void ElfMemImage::Init(const void *base) {
         break;
     }
   }
-  if (!hash_ || !dynsym_ || !dynstr_ || !versym_ ||
+  if ((!sysv_hash && !gnu_hash) || !dynsym_ || !dynstr_ || !versym_ ||
       !verdef_ || !verdefnum_ || !strsize_) {
     assert(false);  // invalid VDSO
     // Mark this image as not present. Can not recur infinitely.
     Init(nullptr);
     return;
   }
+  if (sysv_hash) {
+    num_syms_ = sysv_hash[1];
+  } else {
+    assert(gnu_hash);
+    // Compute the number of symbols for DT_GNU_HASH, which is specified by
+    // https://sourceware.org/gnu-gabi/program-loading-and-dynamic-linking.txt
+    uint32_t nbuckets = gnu_hash[0];
+    // The buckets array is located after the header (4 uint32) and the bloom
+    // filter (size_t array of gnu_hash[2] elements).
+    uint32_t *buckets = gnu_hash + 4 + sizeof(size_t) / 4 * gnu_hash[2];
+    // Find the chain of the last non-empty bucket.
+    uint32_t idx = 0;
+    for (uint32_t i = nbuckets; i > 0;) {
+      idx = buckets[--i];
+      if (idx != 0) break;
+    }
+    if (idx != 0) {
+      // Find the last element of the chain, which has an odd value.
+      // Add one to get the number of symbols.
+      uint32_t *chain = buckets + nbuckets - gnu_hash[1];
+      while (chain[idx++] % 2 == 0) {
+      }
+    }
+    num_syms_ = idx;
+  }
 }
 
 bool ElfMemImage::LookupSymbol(const char *name,
@@ -300,9 +327,9 @@ bool ElfMemImage::LookupSymbolByAddress(const void *address,
   return false;
 }
 
-ElfMemImage::SymbolIterator::SymbolIterator(const void *const image, int index)
-    : index_(index), image_(image) {
-}
+ElfMemImage::SymbolIterator::SymbolIterator(const void *const image,
+                                            uint32_t index)
+    : index_(index), image_(image) {}
 
 const ElfMemImage::SymbolInfo *ElfMemImage::SymbolIterator::operator->() const {
   return &info_;
@@ -335,7 +362,7 @@ ElfMemImage::SymbolIterator ElfMemImage::end() const {
   return SymbolIterator(this, GetNumSymbols());
 }
 
-void ElfMemImage::SymbolIterator::Update(int increment) {
+void ElfMemImage::SymbolIterator::Update(uint32_t increment) {
   const ElfMemImage *image = reinterpret_cast<const ElfMemImage *>(image_);
   Y_ABSL_RAW_CHECK(image->IsPresent() || increment == 0, "");
   if (!image->IsPresent()) {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.h
index 9c5e588fbb..4a3ee56edf 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/elf_mem_image.h
@@ -22,6 +22,7 @@
 // Including this will define the __GLIBC__ macro if glibc is being
 // used.
 #include <climits>
+#include <cstdint>
 
 #include "y_absl/base/config.h"
 
@@ -82,10 +83,10 @@ class ElfMemImage {
     bool operator!=(const SymbolIterator &rhs) const;
     bool operator==(const SymbolIterator &rhs) const;
    private:
-    SymbolIterator(const void *const image, int index);
-    void Update(int incr);
+    SymbolIterator(const void *const image, uint32_t index);
+    void Update(uint32_t incr);
     SymbolInfo info_;
-    int index_;
+    uint32_t index_;
     const void *const image_;
   };
 
@@ -94,14 +95,14 @@ class ElfMemImage {
   void                 Init(const void *base);
   bool                 IsPresent() const { return ehdr_ != nullptr; }
   const ElfW(Phdr)*    GetPhdr(int index) const;
-  const ElfW(Sym)*     GetDynsym(int index) const;
-  const ElfW(Versym)*  GetVersym(int index) const;
+  const ElfW(Sym) * GetDynsym(uint32_t index) const;
+  const ElfW(Versym)*  GetVersym(uint32_t index) const;
   const ElfW(Verdef)*  GetVerdef(int index) const;
   const ElfW(Verdaux)* GetVerdefAux(const ElfW(Verdef) *verdef) const;
   const char*          GetDynstr(ElfW(Word) offset) const;
   const void*          GetSymAddr(const ElfW(Sym) *sym) const;
   const char*          GetVerstr(ElfW(Word) offset) const;
-  int                  GetNumSymbols() const;
+  uint32_t GetNumSymbols() const;
 
   SymbolIterator begin() const;
   SymbolIterator end() const;
@@ -124,8 +125,8 @@ class ElfMemImage {
   const ElfW(Sym) *dynsym_;
   const ElfW(Versym) *versym_;
   const ElfW(Verdef) *verdef_;
-  const ElfW(Word) *hash_;
   const char *dynstr_;
+  uint32_t num_syms_;
   size_t strsize_;
   size_t verdefnum_;
   ElfW(Addr) link_base_;     // Link-time base (p_vaddr of first PT_LOAD).
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/stacktrace_aarch64-inl.inc b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/stacktrace_aarch64-inl.inc
index 7c7c0304e3..1bf78f03e1 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/stacktrace_aarch64-inl.inc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/stacktrace_aarch64-inl.inc
@@ -89,6 +89,8 @@ struct StackInfo {
 
 static bool InsideSignalStack(void** ptr, const StackInfo* stack_info) {
   uintptr_t comparable_ptr = reinterpret_cast<uintptr_t>(ptr);
+  if (stack_info->sig_stack_high == kUnknownStackEnd)
+    return false;
   return (comparable_ptr >= stack_info->sig_stack_low &&
           comparable_ptr < stack_info->sig_stack_high);
 }
@@ -122,13 +124,6 @@ static void **NextStackFrame(void **old_frame_pointer, const void *uc,
       if (pre_signal_frame_pointer >= old_frame_pointer) {
         new_frame_pointer = pre_signal_frame_pointer;
       }
-      // Check that alleged frame pointer is actually readable. This is to
-      // prevent "double fault" in case we hit the first fault due to e.g.
-      // stack corruption.
-      if (!y_absl::debugging_internal::AddressIsReadable(
-              new_frame_pointer))
-        return nullptr;
-    }
   }
 #endif
 
@@ -136,6 +131,14 @@ static void **NextStackFrame(void **old_frame_pointer, const void *uc,
   if ((reinterpret_cast<uintptr_t>(new_frame_pointer) & 7) != 0)
     return nullptr;
 
+  // Check that alleged frame pointer is actually readable. This is to
+  // prevent "double fault" in case we hit the first fault due to e.g.
+  // stack corruption.
+  if (!y_absl::debugging_internal::AddressIsReadable(
+          new_frame_pointer))
+    return nullptr;
+  }
+
   // Only check the size if both frames are in the same stack.
   if (InsideSignalStack(new_frame_pointer, stack_info) ==
       InsideSignalStack(old_frame_pointer, stack_info)) {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/utf8_for_code_point.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/utf8_for_code_point.cc
new file mode 100644
index 0000000000..ed158c62b3
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/utf8_for_code_point.cc
@@ -0,0 +1,70 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "y_absl/debugging/internal/utf8_for_code_point.h"
+
+#include <cstdint>
+
+#include "y_absl/base/config.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+// UTF-8 encoding bounds.
+constexpr uint32_t kMinSurrogate = 0xd800, kMaxSurrogate = 0xdfff;
+constexpr uint32_t kMax1ByteCodePoint = 0x7f;
+constexpr uint32_t kMax2ByteCodePoint = 0x7ff;
+constexpr uint32_t kMax3ByteCodePoint = 0xffff;
+constexpr uint32_t kMaxCodePoint = 0x10ffff;
+
+}  // namespace
+
+Utf8ForCodePoint::Utf8ForCodePoint(uint64_t code_point) {
+  if (code_point <= kMax1ByteCodePoint) {
+    length = 1;
+    bytes[0] = static_cast<char>(code_point);
+    return;
+  }
+
+  if (code_point <= kMax2ByteCodePoint) {
+    length = 2;
+    bytes[0] = static_cast<char>(0xc0 | (code_point >> 6));
+    bytes[1] = static_cast<char>(0x80 | (code_point & 0x3f));
+    return;
+  }
+
+  if (kMinSurrogate <= code_point && code_point <= kMaxSurrogate) return;
+
+  if (code_point <= kMax3ByteCodePoint) {
+    length = 3;
+    bytes[0] = static_cast<char>(0xe0 | (code_point >> 12));
+    bytes[1] = static_cast<char>(0x80 | ((code_point >> 6) & 0x3f));
+    bytes[2] = static_cast<char>(0x80 | (code_point & 0x3f));
+    return;
+  }
+
+  if (code_point > kMaxCodePoint) return;
+
+  length = 4;
+  bytes[0] = static_cast<char>(0xf0 | (code_point >> 18));
+  bytes[1] = static_cast<char>(0x80 | ((code_point >> 12) & 0x3f));
+  bytes[2] = static_cast<char>(0x80 | ((code_point >> 6) & 0x3f));
+  bytes[3] = static_cast<char>(0x80 | (code_point & 0x3f));
+}
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/utf8_for_code_point.h b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/utf8_for_code_point.h
new file mode 100644
index 0000000000..aa0dc65b82
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/internal/utf8_for_code_point.h
@@ -0,0 +1,47 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef Y_ABSL_DEBUGGING_INTERNAL_UTF8_FOR_CODE_POINT_H_
+#define Y_ABSL_DEBUGGING_INTERNAL_UTF8_FOR_CODE_POINT_H_
+
+#include <cstdint>
+
+#include "y_absl/base/config.h"
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+struct Utf8ForCodePoint {
+  // Converts a Unicode code point to the corresponding UTF-8 byte sequence.
+  // Async-signal-safe to support use in symbolizing stack traces from a signal
+  // handler.
+  explicit Utf8ForCodePoint(uint64_t code_point);
+
+  // Returns true if the constructor's code_point argument was valid.
+  bool ok() const { return length != 0; }
+
+  // If code_point was in range, then 1 <= length <= 4, and the UTF-8 encoding
+  // is found in bytes[0 .. (length - 1)].  If code_point was invalid, then
+  // length == 0.  In either case, the contents of bytes[length .. 3] are
+  // unspecified.
+  char bytes[4] = {};
+  uint32_t length = 0;
+};
+
+}  // namespace debugging_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_DEBUGGING_INTERNAL_UTF8_FOR_CODE_POINT_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/ya.make
index 0ceb1cd2ca..d16ebf04dd 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/debugging/ya.make
@@ -20,9 +20,12 @@ NO_COMPILER_WARNINGS()
 SRCS(
     failure_signal_handler.cc
     internal/address_is_readable.cc
+    internal/decode_rust_punycode.cc
     internal/demangle.cc
+    internal/demangle_rust.cc
     internal/elf_mem_image.cc
     internal/examine_stack.cc
+    internal/utf8_for_code_point.cc
     internal/vdso_support.cc
     leak_check.cc
     stacktrace.cc
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/commandlineflag.h b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/commandlineflag.h
index 1a6f3f5447..47e183ec54 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/commandlineflag.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/commandlineflag.h
@@ -59,6 +59,14 @@ class PrivateHandleAccessor;
 //   // Now you can get flag info from that reflection handle.
 //   TString flag_location = my_flag_data->Filename();
 //   ...
+
+// These are only used as constexpr global objects.
+// They do not use a virtual destructor to simplify their implementation.
+// They are not destroyed except at program exit, so leaks do not matter.
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
 class CommandLineFlag {
  public:
   constexpr CommandLineFlag() = default;
@@ -193,6 +201,9 @@ class CommandLineFlag {
   // flag's value type.
   virtual void CheckDefaultValueParsingRoundtrip() const = 0;
 };
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
 
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/flag.h b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/flag.h
index 68a649b089..ab36ad427d 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/flag.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/flag.h
@@ -29,12 +29,14 @@
 #ifndef Y_ABSL_FLAGS_FLAG_H_
 #define Y_ABSL_FLAGS_FLAG_H_
 
+#include <cstdint>
 #include <util/generic/string.h>
 #include <type_traits>
 
 #include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/optimization.h"
+#include "y_absl/flags/commandlineflag.h"
 #include "y_absl/flags/config.h"
 #include "y_absl/flags/internal/flag.h"
 #include "y_absl/flags/internal/registry.h"
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.cc
index 2e43977966..a007823221 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.cc
@@ -22,14 +22,17 @@
 
 #include <array>
 #include <atomic>
+#include <cstring>
 #include <memory>
-#include <new>
 #include <util/generic/string.h>
 #include <typeinfo>
+#include <vector>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/call_once.h"
 #include "y_absl/base/casts.h"
 #include "y_absl/base/config.h"
+#include "y_absl/base/const_init.h"
 #include "y_absl/base/dynamic_annotations.h"
 #include "y_absl/base/optimization.h"
 #include "y_absl/flags/config.h"
@@ -44,10 +47,9 @@ namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
 namespace flags_internal {
 
-// The help message indicating that the commandline flag has been
-// 'stripped'. It will not show up when doing "-help" and its
-// variants. The flag is stripped if Y_ABSL_FLAGS_STRIP_HELP is set to 1
-// before including y_absl/flags/flag.h
+// The help message indicating that the commandline flag has been stripped. It
+// will not show up when doing "-help" and its variants. The flag is stripped
+// if Y_ABSL_FLAGS_STRIP_HELP is set to 1 before including y_absl/flags/flag.h
 const char kStrippedFlagHelp[] = "\001\002\003\004 (unknown) \004\003\002\001";
 
 namespace {
@@ -78,9 +80,32 @@ class MutexRelock {
   y_absl::Mutex& mu_;
 };
 
+// This is a freelist of leaked flag values and guard for its access.
+// When we can't guarantee it is safe to reuse the memory for flag values,
+// we move the memory to the freelist where it lives indefinitely, so it can
+// still be safely accessed. This also prevents leak checkers from complaining
+// about the leaked memory that can no longer be accessed through any pointer.
+Y_ABSL_CONST_INIT y_absl::Mutex s_freelist_guard(y_absl::kConstInit);
+Y_ABSL_CONST_INIT std::vector<void*>* s_freelist = nullptr;
+
+void AddToFreelist(void* p) {
+  y_absl::MutexLock l(&s_freelist_guard);
+  if (!s_freelist) {
+    s_freelist = new std::vector<void*>;
+  }
+  s_freelist->push_back(p);
+}
+
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
+
+uint64_t NumLeakedFlagValues() {
+  y_absl::MutexLock l(&s_freelist_guard);
+  return s_freelist == nullptr ? 0u : s_freelist->size();
+}
+
+///////////////////////////////////////////////////////////////////////////////
 // Persistent state of the flag data.
 
 class FlagImpl;
@@ -97,7 +122,7 @@ class FlagState : public flags_internal::FlagStateInterface {
         counter_(counter) {}
 
   ~FlagState() override {
-    if (flag_impl_.ValueStorageKind() != FlagValueStorageKind::kAlignedBuffer &&
+    if (flag_impl_.ValueStorageKind() != FlagValueStorageKind::kHeapAllocated &&
         flag_impl_.ValueStorageKind() != FlagValueStorageKind::kSequenceLocked)
       return;
     flags_internal::Delete(flag_impl_.op_, value_.heap_allocated);
@@ -140,6 +165,33 @@ void DynValueDeleter::operator()(void* ptr) const {
   Delete(op, ptr);
 }
 
+MaskedPointer::MaskedPointer(ptr_t rhs, bool is_candidate) : ptr_(rhs) {
+  if (is_candidate) {
+    ApplyMask(kUnprotectedReadCandidate);
+  }
+}
+
+bool MaskedPointer::IsUnprotectedReadCandidate() const {
+  return CheckMask(kUnprotectedReadCandidate);
+}
+
+bool MaskedPointer::HasBeenRead() const { return CheckMask(kHasBeenRead); }
+
+void MaskedPointer::Set(FlagOpFn op, const void* src, bool is_candidate) {
+  flags_internal::Copy(op, src, Ptr());
+  if (is_candidate) {
+    ApplyMask(kUnprotectedReadCandidate);
+  }
+}
+void MaskedPointer::MarkAsRead() { ApplyMask(kHasBeenRead); }
+
+void MaskedPointer::ApplyMask(mask_t mask) {
+  ptr_ = reinterpret_cast<ptr_t>(reinterpret_cast<mask_t>(ptr_) | mask);
+}
+bool MaskedPointer::CheckMask(mask_t mask) const {
+  return (reinterpret_cast<mask_t>(ptr_) & mask) != 0;
+}
+
 void FlagImpl::Init() {
   new (&data_guard_) y_absl::Mutex;
 
@@ -174,11 +226,16 @@ void FlagImpl::Init() {
       (*default_value_.gen_func)(AtomicBufferValue());
       break;
     }
-    case FlagValueStorageKind::kAlignedBuffer:
+    case FlagValueStorageKind::kHeapAllocated:
       // For this storage kind the default_value_ always points to gen_func
       // during initialization.
       assert(def_kind == FlagDefaultKind::kGenFunc);
-      (*default_value_.gen_func)(AlignedBufferValue());
+      // Flag value initially points to the internal buffer.
+      MaskedPointer ptr_value = PtrStorage().load(std::memory_order_acquire);
+      (*default_value_.gen_func)(ptr_value.Ptr());
+      // Default value is a candidate for an unprotected read.
+      PtrStorage().store(MaskedPointer(ptr_value.Ptr(), true),
+                         std::memory_order_release);
       break;
   }
   seq_lock_.MarkInitialized();
@@ -234,7 +291,7 @@ std::unique_ptr<void, DynValueDeleter> FlagImpl::MakeInitValue() const {
   return {res, DynValueDeleter{op_}};
 }
 
-void FlagImpl::StoreValue(const void* src) {
+void FlagImpl::StoreValue(const void* src, ValueSource source) {
   switch (ValueStorageKind()) {
     case FlagValueStorageKind::kValueAndInitBit:
     case FlagValueStorageKind::kOneWordAtomic: {
@@ -249,8 +306,27 @@ void FlagImpl::StoreValue(const void* src) {
       seq_lock_.Write(AtomicBufferValue(), src, Sizeof(op_));
       break;
     }
-    case FlagValueStorageKind::kAlignedBuffer:
-      Copy(op_, src, AlignedBufferValue());
+    case FlagValueStorageKind::kHeapAllocated:
+      MaskedPointer ptr_value = PtrStorage().load(std::memory_order_acquire);
+
+      if (ptr_value.IsUnprotectedReadCandidate() && ptr_value.HasBeenRead()) {
+        // If current value is a candidate for an unprotected read and if it was
+        // already read at least once, follow up reads (if any) are done without
+        // mutex protection. We can't guarantee it is safe to reuse this memory
+        // since it may have been accessed by another thread concurrently, so
+        // instead we move the memory to a freelist so it can still be safely
+        // accessed, and allocate a new one for the new value.
+        AddToFreelist(ptr_value.Ptr());
+        ptr_value = MaskedPointer(Clone(op_, src), source == kCommandLine);
+      } else {
+        // Current value either was set programmatically or was never read.
+        // We can reuse the memory since all accesses to this value (if any)
+        // were protected by mutex. That said, if a new value comes from command
+        // line it now becomes a candidate for an unprotected read.
+        ptr_value.Set(op_, src, source == kCommandLine);
+      }
+
+      PtrStorage().store(ptr_value, std::memory_order_release);
       seq_lock_.IncrementModificationCount();
       break;
   }
@@ -305,9 +381,10 @@ TString FlagImpl::CurrentValue() const {
       ReadSequenceLockedData(cloned.get());
       return flags_internal::Unparse(op_, cloned.get());
     }
-    case FlagValueStorageKind::kAlignedBuffer: {
+    case FlagValueStorageKind::kHeapAllocated: {
       y_absl::MutexLock l(guard);
-      return flags_internal::Unparse(op_, AlignedBufferValue());
+      return flags_internal::Unparse(
+          op_, PtrStorage().load(std::memory_order_acquire).Ptr());
     }
   }
 
@@ -370,10 +447,12 @@ std::unique_ptr<FlagStateInterface> FlagImpl::SaveState() {
       return y_absl::make_unique<FlagState>(*this, cloned, modified,
                                           on_command_line, ModificationCount());
     }
-    case FlagValueStorageKind::kAlignedBuffer: {
+    case FlagValueStorageKind::kHeapAllocated: {
       return y_absl::make_unique<FlagState>(
-          *this, flags_internal::Clone(op_, AlignedBufferValue()), modified,
-          on_command_line, ModificationCount());
+          *this,
+          flags_internal::Clone(
+              op_, PtrStorage().load(std::memory_order_acquire).Ptr()),
+          modified, on_command_line, ModificationCount());
     }
   }
   return nullptr;
@@ -388,11 +467,11 @@ bool FlagImpl::RestoreState(const FlagState& flag_state) {
   switch (ValueStorageKind()) {
     case FlagValueStorageKind::kValueAndInitBit:
     case FlagValueStorageKind::kOneWordAtomic:
-      StoreValue(&flag_state.value_.one_word);
+      StoreValue(&flag_state.value_.one_word, kProgrammaticChange);
       break;
     case FlagValueStorageKind::kSequenceLocked:
-    case FlagValueStorageKind::kAlignedBuffer:
-      StoreValue(flag_state.value_.heap_allocated);
+    case FlagValueStorageKind::kHeapAllocated:
+      StoreValue(flag_state.value_.heap_allocated, kProgrammaticChange);
       break;
   }
 
@@ -411,11 +490,6 @@ StorageT* FlagImpl::OffsetValue() const {
   return reinterpret_cast<StorageT*>(p + offset);
 }
 
-void* FlagImpl::AlignedBufferValue() const {
-  assert(ValueStorageKind() == FlagValueStorageKind::kAlignedBuffer);
-  return OffsetValue<void>();
-}
-
 std::atomic<uint64_t>* FlagImpl::AtomicBufferValue() const {
   assert(ValueStorageKind() == FlagValueStorageKind::kSequenceLocked);
   return OffsetValue<std::atomic<uint64_t>>();
@@ -427,6 +501,11 @@ std::atomic<int64_t>& FlagImpl::OneWordValue() const {
   return OffsetValue<FlagOneWordValue>()->value;
 }
 
+std::atomic<MaskedPointer>& FlagImpl::PtrStorage() const {
+  assert(ValueStorageKind() == FlagValueStorageKind::kHeapAllocated);
+  return OffsetValue<FlagMaskedPointerValue>()->value;
+}
+
 // Attempts to parse supplied `value` string using parsing routine in the `flag`
 // argument. If parsing successful, this function replaces the dst with newly
 // parsed value. In case if any error is encountered in either step, the error
@@ -460,9 +539,17 @@ void FlagImpl::Read(void* dst) const {
       ReadSequenceLockedData(dst);
       break;
     }
-    case FlagValueStorageKind::kAlignedBuffer: {
+    case FlagValueStorageKind::kHeapAllocated: {
       y_absl::MutexLock l(guard);
-      flags_internal::CopyConstruct(op_, AlignedBufferValue(), dst);
+      MaskedPointer ptr_value = PtrStorage().load(std::memory_order_acquire);
+
+      flags_internal::CopyConstruct(op_, ptr_value.Ptr(), dst);
+
+      // For unprotected read candidates, mark that the value as has been read.
+      if (ptr_value.IsUnprotectedReadCandidate() && !ptr_value.HasBeenRead()) {
+        ptr_value.MarkAsRead();
+        PtrStorage().store(ptr_value, std::memory_order_release);
+      }
       break;
     }
   }
@@ -513,7 +600,7 @@ void FlagImpl::Write(const void* src) {
     }
   }
 
-  StoreValue(src);
+  StoreValue(src, kProgrammaticChange);
 }
 
 // Sets the value of the flag based on specified string `value`. If the flag
@@ -534,7 +621,7 @@ bool FlagImpl::ParseFrom(y_absl::string_view value, FlagSettingMode set_mode,
       auto tentative_value = TryParse(value, err);
       if (!tentative_value) return false;
 
-      StoreValue(tentative_value.get());
+      StoreValue(tentative_value.get(), source);
 
       if (source == kCommandLine) {
         on_command_line_ = true;
@@ -555,7 +642,7 @@ bool FlagImpl::ParseFrom(y_absl::string_view value, FlagSettingMode set_mode,
       auto tentative_value = TryParse(value, err);
       if (!tentative_value) return false;
 
-      StoreValue(tentative_value.get());
+      StoreValue(tentative_value.get(), source);
       break;
     }
     case SET_FLAGS_DEFAULT: {
@@ -573,7 +660,7 @@ bool FlagImpl::ParseFrom(y_absl::string_view value, FlagSettingMode set_mode,
 
       if (!modified_) {
         // Need to set both default value *and* current, in this case.
-        StoreValue(default_value_.dynamic_value);
+        StoreValue(default_value_.dynamic_value, source);
         modified_ = false;
       }
       break;
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.h b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.h
index ecccfe0edb..6a3b2c1376 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/internal/flag.h
@@ -22,7 +22,6 @@
 #include <atomic>
 #include <cstring>
 #include <memory>
-#include <new>
 #include <util/generic/string.h>
 #include <type_traits>
 #include <typeinfo>
@@ -296,11 +295,8 @@ constexpr FlagDefaultArg DefaultArg(char) {
 }
 
 ///////////////////////////////////////////////////////////////////////////////
-// Flag current value auxiliary structs.
-
-constexpr int64_t UninitializedFlagValue() {
-  return static_cast<int64_t>(0xababababababababll);
-}
+// Flag storage selector traits. Each trait indicates what kind of storage kind
+// to use for the flag value.
 
 template <typename T>
 using FlagUseValueAndInitBitStorage =
@@ -322,9 +318,11 @@ enum class FlagValueStorageKind : uint8_t {
   kValueAndInitBit = 0,
   kOneWordAtomic = 1,
   kSequenceLocked = 2,
-  kAlignedBuffer = 3,
+  kHeapAllocated = 3,
 };
 
+// This constexpr function returns the storage kind for the given flag value
+// type.
 template <typename T>
 static constexpr FlagValueStorageKind StorageKind() {
   return FlagUseValueAndInitBitStorage<T>::value
@@ -333,14 +331,24 @@ static constexpr FlagValueStorageKind StorageKind() {
              ? FlagValueStorageKind::kOneWordAtomic
          : FlagUseSequenceLockStorage<T>::value
              ? FlagValueStorageKind::kSequenceLocked
-             : FlagValueStorageKind::kAlignedBuffer;
+             : FlagValueStorageKind::kHeapAllocated;
 }
 
+// This is a base class for the storage classes used by kOneWordAtomic and
+// kValueAndInitBit storage kinds. It literally just stores the one word value
+// as an atomic. By default, it is initialized to a magic value that is unlikely
+// a valid value for the flag value type.
 struct FlagOneWordValue {
+  constexpr static int64_t Uninitialized() {
+    return static_cast<int64_t>(0xababababababababll);
+  }
+
+  constexpr FlagOneWordValue() : value(Uninitialized()) {}
   constexpr explicit FlagOneWordValue(int64_t v) : value(v) {}
   std::atomic<int64_t> value;
 };
 
+// This class represents a memory layout used by kValueAndInitBit storage kind.
 template <typename T>
 struct alignas(8) FlagValueAndInitBit {
   T value;
@@ -349,16 +357,91 @@ struct alignas(8) FlagValueAndInitBit {
   uint8_t init;
 };
 
+// This class implements an aligned pointer with two options stored via masks
+// in unused bits of the pointer value (due to alignment requirement).
+//  - IsUnprotectedReadCandidate - indicates that the value can be switched to
+//    unprotected read without a lock.
+//  - HasBeenRead - indicates that the value has been read at least once.
+//  - AllowsUnprotectedRead - combination of the two options above and indicates
+//    that the value can now be read without a lock.
+// Further details of these options and their use is covered in the description
+// of the FlagValue<T, FlagValueStorageKind::kHeapAllocated> specialization.
+class MaskedPointer {
+ public:
+  using mask_t = uintptr_t;
+  using ptr_t = void*;
+
+  static constexpr int RequiredAlignment() { return 4; }
+
+  constexpr explicit MaskedPointer(ptr_t rhs) : ptr_(rhs) {}
+  MaskedPointer(ptr_t rhs, bool is_candidate);
+
+  void* Ptr() const {
+    return reinterpret_cast<void*>(reinterpret_cast<mask_t>(ptr_) &
+                                   kPtrValueMask);
+  }
+  bool AllowsUnprotectedRead() const {
+    return (reinterpret_cast<mask_t>(ptr_) & kAllowsUnprotectedRead) ==
+           kAllowsUnprotectedRead;
+  }
+  bool IsUnprotectedReadCandidate() const;
+  bool HasBeenRead() const;
+
+  void Set(FlagOpFn op, const void* src, bool is_candidate);
+  void MarkAsRead();
+
+ private:
+  // Masks
+  // Indicates that the flag value either default or originated from command
+  // line.
+  static constexpr mask_t kUnprotectedReadCandidate = 0x1u;
+  // Indicates that flag has been read.
+  static constexpr mask_t kHasBeenRead = 0x2u;
+  static constexpr mask_t kAllowsUnprotectedRead =
+      kUnprotectedReadCandidate | kHasBeenRead;
+  static constexpr mask_t kPtrValueMask = ~kAllowsUnprotectedRead;
+
+  void ApplyMask(mask_t mask);
+  bool CheckMask(mask_t mask) const;
+
+  ptr_t ptr_;
+};
+
+// This class implements a type erased storage of the heap allocated flag value.
+// It is used as a base class for the storage class for kHeapAllocated storage
+// kind. The initial_buffer is expected to have an alignment of at least
+// MaskedPointer::RequiredAlignment(), so that the bits used by the
+// MaskedPointer to store masks are set to 0. This guarantees that value starts
+// in an uninitialized state.
+struct FlagMaskedPointerValue {
+  constexpr explicit FlagMaskedPointerValue(MaskedPointer::ptr_t initial_buffer)
+      : value(MaskedPointer(initial_buffer)) {}
+
+  std::atomic<MaskedPointer> value;
+};
+
+// This is the forward declaration for the template that represents a storage
+// for the flag values. This template is expected to be explicitly specialized
+// for each storage kind and it does not have a generic default
+// implementation.
 template <typename T,
           FlagValueStorageKind Kind = flags_internal::StorageKind<T>()>
 struct FlagValue;
 
+// This specialization represents the storage of flag values types with the
+// kValueAndInitBit storage kind. It is based on the FlagOneWordValue class
+// and relies on memory layout in FlagValueAndInitBit<T> to indicate that the
+// value has been initialized or not.
 template <typename T>
 struct FlagValue<T, FlagValueStorageKind::kValueAndInitBit> : FlagOneWordValue {
   constexpr FlagValue() : FlagOneWordValue(0) {}
   bool Get(const SequenceLock&, T& dst) const {
     int64_t storage = value.load(std::memory_order_acquire);
     if (Y_ABSL_PREDICT_FALSE(storage == 0)) {
+      // This assert is to ensure that the initialization inside FlagImpl::Init
+      // is able to set init member correctly.
+      static_assert(offsetof(FlagValueAndInitBit<T>, init) == sizeof(T),
+                    "Unexpected memory layout of FlagValueAndInitBit");
       return false;
     }
     dst = y_absl::bit_cast<FlagValueAndInitBit<T>>(storage).value;
@@ -366,12 +449,16 @@ struct FlagValue<T, FlagValueStorageKind::kValueAndInitBit> : FlagOneWordValue {
   }
 };
 
+// This specialization represents the storage of flag values types with the
+// kOneWordAtomic storage kind. It is based on the FlagOneWordValue class
+// and relies on the magic uninitialized state of default constructed instead of
+// FlagOneWordValue to indicate that the value has been initialized or not.
 template <typename T>
 struct FlagValue<T, FlagValueStorageKind::kOneWordAtomic> : FlagOneWordValue {
-  constexpr FlagValue() : FlagOneWordValue(UninitializedFlagValue()) {}
+  constexpr FlagValue() : FlagOneWordValue() {}
   bool Get(const SequenceLock&, T& dst) const {
     int64_t one_word_val = value.load(std::memory_order_acquire);
-    if (Y_ABSL_PREDICT_FALSE(one_word_val == UninitializedFlagValue())) {
+    if (Y_ABSL_PREDICT_FALSE(one_word_val == FlagOneWordValue::Uninitialized())) {
       return false;
     }
     std::memcpy(&dst, static_cast<const void*>(&one_word_val), sizeof(T));
@@ -379,6 +466,12 @@ struct FlagValue<T, FlagValueStorageKind::kOneWordAtomic> : FlagOneWordValue {
   }
 };
 
+// This specialization represents the storage of flag values types with the
+// kSequenceLocked storage kind. This storage is used by trivially copyable
+// types with size greater than 8 bytes. This storage relies on uninitialized
+// state of the SequenceLock to indicate that the value has been initialized or
+// not. This storage also provides lock-free read access to the underlying
+// value once it is initialized.
 template <typename T>
 struct FlagValue<T, FlagValueStorageKind::kSequenceLocked> {
   bool Get(const SequenceLock& lock, T& dst) const {
@@ -392,11 +485,62 @@ struct FlagValue<T, FlagValueStorageKind::kSequenceLocked> {
       std::atomic<uint64_t>) std::atomic<uint64_t> value_words[kNumWords];
 };
 
+// This specialization represents the storage of flag values types with the
+// kHeapAllocated storage kind. This is a storage of last resort and is used
+// if none of other storage kinds are applicable.
+//
+// Generally speaking the values with this storage kind can't be accessed
+// atomically and thus can't be read without holding a lock. If we would ever
+// want to avoid the lock, we'd need to leak the old value every time new flag
+// value is being set (since we are in danger of having a race condition
+// otherwise).
+//
+// Instead of doing that, this implementation attempts to cater to some common
+// use cases by allowing at most 2 values to be leaked - default value and
+// value set from the command line.
+//
+// This specialization provides an initial buffer for the first flag value. This
+// is where the default value is going to be stored. We attempt to reuse this
+// buffer if possible, including storing the value set from the command line
+// there.
+//
+// As long as we only read this value, we can access it without a lock (in
+// practice we still use the lock for the very first read to be able set
+// "has been read" option on this flag).
+//
+// If flag is specified on the command line we store the parsed value either
+// in the internal buffer (if the default value never been read) or we leak the
+// default value and allocate the new storage for the parse value. This value is
+// also a candidate for an unprotected read. If flag is set programmatically
+// after the command line is parsed, the storage for this value is going to be
+// leaked. Note that in both scenarios we are not going to have a real leak.
+// Instead we'll store the leaked value pointers in the internal freelist to
+// avoid triggering the memory leak checker complains.
+//
+// If the flag is ever set programmatically, it stops being the candidate for an
+// unprotected read, and any follow up access to the flag value requires a lock.
+// Note that if the value if set programmatically before the command line is
+// parsed, we can switch back to enabling unprotected reads for that value.
 template <typename T>
-struct FlagValue<T, FlagValueStorageKind::kAlignedBuffer> {
-  bool Get(const SequenceLock&, T&) const { return false; }
+struct FlagValue<T, FlagValueStorageKind::kHeapAllocated>
+    : FlagMaskedPointerValue {
+  // We const initialize the value with unmasked pointer to the internal buffer,
+  // making sure it is not a candidate for unprotected read. This way we can
+  // ensure Init is done before any access to the flag value.
+  constexpr FlagValue() : FlagMaskedPointerValue(&buffer[0]) {}
+
+  bool Get(const SequenceLock&, T& dst) const {
+    MaskedPointer ptr_value = value.load(std::memory_order_acquire);
 
-  alignas(T) char value[sizeof(T)];
+    if (Y_ABSL_PREDICT_TRUE(ptr_value.AllowsUnprotectedRead())) {
+      ::new (static_cast<void*>(&dst)) T(*static_cast<T*>(ptr_value.Ptr()));
+      return true;
+    }
+    return false;
+  }
+
+  alignas(MaskedPointer::RequiredAlignment()) alignas(
+      T) char buffer[sizeof(T)]{};
 };
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -425,6 +569,13 @@ struct DynValueDeleter {
 
 class FlagState;
 
+// These are only used as constexpr global objects.
+// They do not use a virtual destructor to simplify their implementation.
+// They are not destroyed except at program exit, so leaks do not matter.
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
 class FlagImpl final : public CommandLineFlag {
  public:
   constexpr FlagImpl(const char* name, const char* filename, FlagOpFn op,
@@ -477,7 +628,7 @@ class FlagImpl final : public CommandLineFlag {
   // Used in read/write operations to validate source/target has correct type.
   // For example if flag is declared as y_absl::Flag<int> FLAGS_foo, a call to
   // y_absl::GetFlag(FLAGS_foo) validates that the type of FLAGS_foo is indeed
-  // int. To do that we pass the "assumed" type id (which is deduced from type
+  // int. To do that we pass the assumed type id (which is deduced from type
   // int) as an argument `type_id`, which is in turn is validated against the
   // type id stored in flag object by flag definition statement.
   void AssertValidType(FlagFastTypeId type_id,
@@ -498,17 +649,13 @@ class FlagImpl final : public CommandLineFlag {
   void Init();
 
   // Offset value access methods. One per storage kind. These methods to not
-  // respect const correctness, so be very carefull using them.
+  // respect const correctness, so be very careful using them.
 
   // This is a shared helper routine which encapsulates most of the magic. Since
   // it is only used inside the three routines below, which are defined in
   // flag.cc, we can define it in that file as well.
   template <typename StorageT>
   StorageT* OffsetValue() const;
-  // This is an accessor for a value stored in an aligned buffer storage
-  // used for non-trivially-copyable data types.
-  // Returns a mutable pointer to the start of a buffer.
-  void* AlignedBufferValue() const;
 
   // The same as above, but used for sequencelock-protected storage.
   std::atomic<uint64_t>* AtomicBufferValue() const;
@@ -517,13 +664,16 @@ class FlagImpl final : public CommandLineFlag {
   // mutable reference to an atomic value.
   std::atomic<int64_t>& OneWordValue() const;
 
+  std::atomic<MaskedPointer>& PtrStorage() const;
+
   // Attempts to parse supplied `value` string. If parsing is successful,
   // returns new value. Otherwise returns nullptr.
   std::unique_ptr<void, DynValueDeleter> TryParse(y_absl::string_view value,
                                                   TString& err) const
       Y_ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
   // Stores the flag value based on the pointer to the source.
-  void StoreValue(const void* src) Y_ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
+  void StoreValue(const void* src, ValueSource source)
+      Y_ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
 
   // Copy the flag data, protected by `seq_lock_` into `dst`.
   //
@@ -579,7 +729,7 @@ class FlagImpl final : public CommandLineFlag {
   const char* const name_;
   // The file name where Y_ABSL_FLAG resides.
   const char* const filename_;
-  // Type-specific operations "vtable".
+  // Type-specific operations vtable.
   const FlagOpFn op_;
   // Help message literal or function to generate it.
   const FlagHelpMsg help_;
@@ -624,6 +774,9 @@ class FlagImpl final : public CommandLineFlag {
   // problems.
   alignas(y_absl::Mutex) mutable char data_guard_[sizeof(y_absl::Mutex)];
 };
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
 
 ///////////////////////////////////////////////////////////////////////////////
 // The Flag object parameterized by the flag's value type. This class implements
@@ -711,16 +864,21 @@ class FlagImplPeer {
 // Implementation of Flag value specific operations routine.
 template <typename T>
 void* FlagOps(FlagOp op, const void* v1, void* v2, void* v3) {
+  struct AlignedSpace {
+    alignas(MaskedPointer::RequiredAlignment()) alignas(T) char buf[sizeof(T)];
+  };
+  using Allocator = std::allocator<AlignedSpace>;
   switch (op) {
     case FlagOp::kAlloc: {
-      std::allocator<T> alloc;
-      return std::allocator_traits<std::allocator<T>>::allocate(alloc, 1);
+      Allocator alloc;
+      return std::allocator_traits<Allocator>::allocate(alloc, 1);
     }
     case FlagOp::kDelete: {
       T* p = static_cast<T*>(v2);
       p->~T();
-      std::allocator<T> alloc;
-      std::allocator_traits<std::allocator<T>>::deallocate(alloc, p, 1);
+      Allocator alloc;
+      std::allocator_traits<Allocator>::deallocate(
+          alloc, reinterpret_cast<AlignedSpace*>(p), 1);
       return nullptr;
     }
     case FlagOp::kCopy:
@@ -754,8 +912,7 @@ void* FlagOps(FlagOp op, const void* v1, void* v2, void* v3) {
       // Round sizeof(FlagImp) to a multiple of alignof(FlagValue<T>) to get the
       // offset of the data.
       size_t round_to = alignof(FlagValue<T>);
-      size_t offset =
-          (sizeof(FlagImpl) + round_to - 1) / round_to * round_to;
+      size_t offset = (sizeof(FlagImpl) + round_to - 1) / round_to * round_to;
       return reinterpret_cast<void*>(offset);
     }
   }
@@ -770,7 +927,8 @@ struct FlagRegistrarEmpty {};
 template <typename T, bool do_register>
 class FlagRegistrar {
  public:
-  explicit FlagRegistrar(Flag<T>& flag, const char* filename) : flag_(flag) {
+  constexpr explicit FlagRegistrar(Flag<T>& flag, const char* filename)
+      : flag_(flag) {
     if (do_register)
       flags_internal::RegisterCommandLineFlag(flag_.impl_, filename);
   }
@@ -780,15 +938,19 @@ class FlagRegistrar {
     return *this;
   }
 
-  // Make the registrar "die" gracefully as an empty struct on a line where
+  // Makes the registrar die gracefully as an empty struct on a line where
   // registration happens. Registrar objects are intended to live only as
   // temporary.
-  operator FlagRegistrarEmpty() const { return {}; }  // NOLINT
+  constexpr operator FlagRegistrarEmpty() const { return {}; }  // NOLINT
 
  private:
   Flag<T>& flag_;  // Flag being registered (not owned).
 };
 
+///////////////////////////////////////////////////////////////////////////////
+// Test only API
+uint64_t NumLeakedFlagValues();
+
 }  // namespace flags_internal
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/reflection.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/reflection.cc
index 61d52e6121..4ecec8411b 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/flags/reflection.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/flags/reflection.cc
@@ -217,6 +217,13 @@ void FinalizeRegistry() {
 
 namespace {
 
+// These are only used as constexpr global objects.
+// They do not use a virtual destructor to simplify their implementation.
+// They are not destroyed except at program exit, so leaks do not matter.
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
 class RetiredFlagObj final : public CommandLineFlag {
  public:
   constexpr RetiredFlagObj(const char* name, FlagFastTypeId type_id)
@@ -276,6 +283,9 @@ class RetiredFlagObj final : public CommandLineFlag {
   const char* const name_;
   const FlagFastTypeId type_id_;
 };
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
 
 }  // namespace
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/any_invocable.h b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/any_invocable.h
index f04000578a..d3e96ad585 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/any_invocable.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/any_invocable.h
@@ -34,6 +34,7 @@
 #define Y_ABSL_FUNCTIONAL_ANY_INVOCABLE_H_
 
 #include <cstddef>
+#include <functional>
 #include <initializer_list>
 #include <type_traits>
 #include <utility>
@@ -98,9 +99,9 @@ Y_ABSL_NAMESPACE_BEGIN
 // `AnyInvocable` also properly respects `const` qualifiers, reference
 // qualifiers, and the `noexcept` specification (only in C++ 17 and beyond) as
 // part of the user-specified function type (e.g.
-// `AnyInvocable<void()&& const noexcept>`). These qualifiers will be applied to
-// the `AnyInvocable` object's `operator()`, and the underlying invocable must
-// be compatible with those qualifiers.
+// `AnyInvocable<void() const && noexcept>`). These qualifiers will be applied
+// to the `AnyInvocable` object's `operator()`, and the underlying invocable
+// must be compatible with those qualifiers.
 //
 // Comparison of const and non-const function types:
 //
@@ -151,6 +152,12 @@ Y_ABSL_NAMESPACE_BEGIN
 //
 // Attempting to call `y_absl::AnyInvocable` multiple times in such a case
 // results in undefined behavior.
+//
+// Invoking an empty `y_absl::AnyInvocable` results in undefined behavior:
+//
+//   // Create an empty instance using the default constructor.
+//   AnyInvocable<void()> empty;
+//   empty();  // WARNING: Undefined behavior!
 template <class Sig>
 class AnyInvocable : private internal_any_invocable::Impl<Sig> {
  private:
@@ -167,6 +174,7 @@ class AnyInvocable : private internal_any_invocable::Impl<Sig> {
   // Constructors
 
   // Constructs the `AnyInvocable` in an empty state.
+  // Invoking it results in undefined behavior.
   AnyInvocable() noexcept = default;
   AnyInvocable(std::nullptr_t) noexcept {}  // NOLINT
 
@@ -277,6 +285,8 @@ class AnyInvocable : private internal_any_invocable::Impl<Sig> {
   // In other words:
   //   std::function<void()> f;  // empty
   //   y_absl::AnyInvocable<void()> a = std::move(f);  // not empty
+  //
+  // Invoking an empty `AnyInvocable` results in undefined behavior.
   explicit operator bool() const noexcept { return this->HasValue(); }
 
   // Invokes the target object of `*this`. `*this` must not be empty.
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/bind_front.h b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/bind_front.h
index 27597c486b..ecb2e62160 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/bind_front.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/bind_front.h
@@ -34,6 +34,8 @@
 #include <functional>  // For std::bind_front.
 #endif  // defined(__cpp_lib_bind_front) && __cpp_lib_bind_front >= 201907L
 
+#include <utility>
+
 #include "y_absl/functional/internal/front_binder.h"
 #include "y_absl/utility/utility.h"
 
@@ -182,8 +184,7 @@ template <class F, class... BoundArgs>
 constexpr functional_internal::bind_front_t<F, BoundArgs...> bind_front(
     F&& func, BoundArgs&&... args) {
   return functional_internal::bind_front_t<F, BoundArgs...>(
-      y_absl::in_place, y_absl::forward<F>(func),
-      y_absl::forward<BoundArgs>(args)...);
+      y_absl::in_place, std::forward<F>(func), std::forward<BoundArgs>(args)...);
 }
 #endif  // defined(__cpp_lib_bind_front) && __cpp_lib_bind_front >= 201907L
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/any_invocable.h b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/any_invocable.h
index 009a54c6b6..17163431ef 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/any_invocable.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/any_invocable.h
@@ -19,11 +19,11 @@
 
 ////////////////////////////////////////////////////////////////////////////////
 //                                                                            //
-// This implementation of the proposed `any_invocable` uses an approach that  //
-// chooses between local storage and remote storage for the contained target  //
-// object based on the target object's size, alignment requirements, and      //
-// whether or not it has a nothrow move constructor. Additional optimizations //
-// are performed when the object is a trivially copyable type [basic.types].  //
+// This implementation chooses between local storage and remote storage for   //
+// the contained target object based on the target object's size, alignment   //
+// requirements, and whether or not it has a nothrow move constructor.        //
+// Additional optimizations are performed when the object is a trivially      //
+// copyable type [basic.types].                                               //
 //                                                                            //
 // There are three datamembers per `AnyInvocable` instance                    //
 //                                                                            //
@@ -39,7 +39,7 @@
 //    target object, directly returning the result.                           //
 //                                                                            //
 // When in the logically empty state, the manager function is an empty        //
-// function and the invoker function is one that would be undefined-behavior  //
+// function and the invoker function is one that would be undefined behavior  //
 // to call.                                                                   //
 //                                                                            //
 // An additional optimization is performed when converting from one           //
@@ -58,12 +58,12 @@
 #include <cstring>
 #include <exception>
 #include <functional>
-#include <initializer_list>
 #include <memory>
 #include <new>
 #include <type_traits>
 #include <utility>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/invoke.h"
 #include "y_absl/base/macros.h"
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/front_binder.h b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/front_binder.h
index e20e1d2666..49fc58c881 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/front_binder.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/internal/front_binder.h
@@ -34,8 +34,8 @@ namespace functional_internal {
 template <class R, class Tuple, size_t... Idx, class... Args>
 R Apply(Tuple&& bound, y_absl::index_sequence<Idx...>, Args&&... free) {
   return base_internal::invoke(
-      y_absl::forward<Tuple>(bound).template get<Idx>()...,
-      y_absl::forward<Args>(free)...);
+      std::forward<Tuple>(bound).template get<Idx>()...,
+      std::forward<Args>(free)...);
 }
 
 template <class F, class... BoundArgs>
@@ -48,13 +48,13 @@ class FrontBinder {
  public:
   template <class... Ts>
   constexpr explicit FrontBinder(y_absl::in_place_t, Ts&&... ts)
-      : bound_args_(y_absl::forward<Ts>(ts)...) {}
+      : bound_args_(std::forward<Ts>(ts)...) {}
 
   template <class... FreeArgs, class R = base_internal::invoke_result_t<
                                    F&, BoundArgs&..., FreeArgs&&...>>
   R operator()(FreeArgs&&... free_args) & {
     return functional_internal::Apply<R>(bound_args_, Idx(),
-                                         y_absl::forward<FreeArgs>(free_args)...);
+                                         std::forward<FreeArgs>(free_args)...);
   }
 
   template <class... FreeArgs,
@@ -62,7 +62,7 @@ class FrontBinder {
                 const F&, const BoundArgs&..., FreeArgs&&...>>
   R operator()(FreeArgs&&... free_args) const& {
     return functional_internal::Apply<R>(bound_args_, Idx(),
-                                         y_absl::forward<FreeArgs>(free_args)...);
+                                         std::forward<FreeArgs>(free_args)...);
   }
 
   template <class... FreeArgs, class R = base_internal::invoke_result_t<
@@ -70,8 +70,8 @@ class FrontBinder {
   R operator()(FreeArgs&&... free_args) && {
     // This overload is called when *this is an rvalue. If some of the bound
     // arguments are stored by value or rvalue reference, we move them.
-    return functional_internal::Apply<R>(y_absl::move(bound_args_), Idx(),
-                                         y_absl::forward<FreeArgs>(free_args)...);
+    return functional_internal::Apply<R>(std::move(bound_args_), Idx(),
+                                         std::forward<FreeArgs>(free_args)...);
   }
 
   template <class... FreeArgs,
@@ -80,8 +80,8 @@ class FrontBinder {
   R operator()(FreeArgs&&... free_args) const&& {
     // This overload is called when *this is an rvalue. If some of the bound
     // arguments are stored by value or rvalue reference, we move them.
-    return functional_internal::Apply<R>(y_absl::move(bound_args_), Idx(),
-                                         y_absl::forward<FreeArgs>(free_args)...);
+    return functional_internal::Apply<R>(std::move(bound_args_), Idx(),
+                                         std::forward<FreeArgs>(free_args)...);
   }
 };
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/ya.make
index ac5695f072..467248d279 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/functional/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/functional/ya.make
@@ -6,9 +6,9 @@ LICENSE(Apache-2.0)
 
 LICENSE_TEXTS(.yandex_meta/licenses.list.txt)
 
-VERSION(20240116.2)
+VERSION(20240722.0)
 
-ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240116.2.tar.gz)
+ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz)
 
 NO_RUNTIME()
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.cc
index 356cb7631c..e335f01be8 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.cc
@@ -61,7 +61,7 @@ constexpr uint64_t kHashSalt[5] = {
 
 uint64_t MixingHashState::LowLevelHashImpl(const unsigned char* data,
                                            size_t len) {
-  return LowLevelHash(data, len, Seed(), kHashSalt);
+  return LowLevelHashLenGt16(data, len, Seed(), kHashSalt);
 }
 
 }  // namespace hash_internal
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.h b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.h
index b289e1fa5f..107afcaa6b 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/hash.h
@@ -24,6 +24,15 @@
 #include <TargetConditionals.h>
 #endif
 
+#include "y_absl/base/config.h"
+
+// For feature testing and determining which headers can be included.
+#if Y_ABSL_INTERNAL_CPLUSPLUS_LANG >= 202002L
+#include <version>
+#else
+#include <ciso646>
+#endif
+
 #include <algorithm>
 #include <array>
 #include <bitset>
@@ -47,7 +56,6 @@
 #include <utility>
 #include <vector>
 
-#include "y_absl/base/config.h"
 #include "y_absl/base/internal/unaligned_access.h"
 #include "y_absl/base/port.h"
 #include "y_absl/container/fixed_array.h"
@@ -61,7 +69,7 @@
 #include "y_absl/types/variant.h"
 #include "y_absl/utility/utility.h"
 
-#if Y_ABSL_INTERNAL_CPLUSPLUS_LANG >= 201703L && \
+#if defined(__cpp_lib_filesystem) && __cpp_lib_filesystem >= 201703L && \
     !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
 #include <filesystem>  // NOLINT
 #endif
@@ -591,7 +599,9 @@ H AbslHashValue(H hash_state, std::basic_string_view<Char> str) {
 #if defined(__cpp_lib_filesystem) && __cpp_lib_filesystem >= 201703L && \
     !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) && \
     (!defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) ||        \
-     __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 130000)
+     __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 130000) &&       \
+    (!defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) ||         \
+     __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101500)
 
 #define Y_ABSL_INTERNAL_STD_FILESYSTEM_PATH_HASH_AVAILABLE 1
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.cc
index 4c491215d9..1f431e0989 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.cc
@@ -14,6 +14,9 @@
 
 #include "y_absl/hash/internal/low_level_hash.h"
 
+#include <cstddef>
+#include <cstdint>
+
 #include "y_absl/base/internal/unaligned_access.h"
 #include "y_absl/base/prefetch.h"
 #include "y_absl/numeric/int128.h"
@@ -28,19 +31,22 @@ static uint64_t Mix(uint64_t v0, uint64_t v1) {
   return y_absl::Uint128Low64(p) ^ y_absl::Uint128High64(p);
 }
 
-uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed,
-                      const uint64_t salt[5]) {
+uint64_t LowLevelHashLenGt16(const void* data, size_t len, uint64_t seed,
+                             const uint64_t salt[5]) {
   // Prefetch the cacheline that data resides in.
   PrefetchToLocalCache(data);
   const uint8_t* ptr = static_cast<const uint8_t*>(data);
   uint64_t starting_length = static_cast<uint64_t>(len);
+  const uint8_t* last_16_ptr = ptr + starting_length - 16;
   uint64_t current_state = seed ^ salt[0];
 
   if (len > 64) {
     // If we have more than 64 bytes, we're going to handle chunks of 64
     // bytes at a time. We're going to build up two separate hash states
     // which we will then hash together.
-    uint64_t duplicated_state = current_state;
+    uint64_t duplicated_state0 = current_state;
+    uint64_t duplicated_state1 = current_state;
+    uint64_t duplicated_state2 = current_state;
 
     do {
       // Always prefetch the next cacheline.
@@ -55,40 +61,72 @@ uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed,
       uint64_t g = y_absl::base_internal::UnalignedLoad64(ptr + 48);
       uint64_t h = y_absl::base_internal::UnalignedLoad64(ptr + 56);
 
-      uint64_t cs0 = Mix(a ^ salt[1], b ^ current_state);
-      uint64_t cs1 = Mix(c ^ salt[2], d ^ current_state);
-      current_state = (cs0 ^ cs1);
+      current_state = Mix(a ^ salt[1], b ^ current_state);
+      duplicated_state0 = Mix(c ^ salt[2], d ^ duplicated_state0);
 
-      uint64_t ds0 = Mix(e ^ salt[3], f ^ duplicated_state);
-      uint64_t ds1 = Mix(g ^ salt[4], h ^ duplicated_state);
-      duplicated_state = (ds0 ^ ds1);
+      duplicated_state1 = Mix(e ^ salt[3], f ^ duplicated_state1);
+      duplicated_state2 = Mix(g ^ salt[4], h ^ duplicated_state2);
 
       ptr += 64;
       len -= 64;
     } while (len > 64);
 
-    current_state = current_state ^ duplicated_state;
+    current_state = (current_state ^ duplicated_state0) ^
+                    (duplicated_state1 + duplicated_state2);
   }
 
   // We now have a data `ptr` with at most 64 bytes and the current state
   // of the hashing state machine stored in current_state.
-  while (len > 16) {
+  if (len > 32) {
     uint64_t a = y_absl::base_internal::UnalignedLoad64(ptr);
     uint64_t b = y_absl::base_internal::UnalignedLoad64(ptr + 8);
+    uint64_t c = y_absl::base_internal::UnalignedLoad64(ptr + 16);
+    uint64_t d = y_absl::base_internal::UnalignedLoad64(ptr + 24);
 
-    current_state = Mix(a ^ salt[1], b ^ current_state);
+    uint64_t cs0 = Mix(a ^ salt[1], b ^ current_state);
+    uint64_t cs1 = Mix(c ^ salt[2], d ^ current_state);
+    current_state = cs0 ^ cs1;
+
+    ptr += 32;
+    len -= 32;
+  }
 
-    ptr += 16;
-    len -= 16;
+  // We now have a data `ptr` with at most 32 bytes and the current state
+  // of the hashing state machine stored in current_state.
+  if (len > 16) {
+    uint64_t a = y_absl::base_internal::UnalignedLoad64(ptr);
+    uint64_t b = y_absl::base_internal::UnalignedLoad64(ptr + 8);
+
+    current_state = Mix(a ^ salt[1], b ^ current_state);
   }
 
-  // We now have a data `ptr` with at most 16 bytes.
+  // We now have a data `ptr` with at least 1 and at most 16 bytes. But we can
+  // safely read from `ptr + len - 16`.
+  uint64_t a = y_absl::base_internal::UnalignedLoad64(last_16_ptr);
+  uint64_t b = y_absl::base_internal::UnalignedLoad64(last_16_ptr + 8);
+
+  return Mix(a ^ salt[1] ^ starting_length, b ^ current_state);
+}
+
+uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed,
+                      const uint64_t salt[5]) {
+  if (len > 16) return LowLevelHashLenGt16(data, len, seed, salt);
+
+  // Prefetch the cacheline that data resides in.
+  PrefetchToLocalCache(data);
+  const uint8_t* ptr = static_cast<const uint8_t*>(data);
+  uint64_t starting_length = static_cast<uint64_t>(len);
+  uint64_t current_state = seed ^ salt[0];
+  if (len == 0) return current_state;
+
   uint64_t a = 0;
   uint64_t b = 0;
+
+  // We now have a data `ptr` with at least 1 and at most 16 bytes.
   if (len > 8) {
     // When we have at least 9 and at most 16 bytes, set A to the first 64
-    // bits of the input and B to the last 64 bits of the input. Yes, they will
-    // overlap in the middle if we are working with less than the full 16
+    // bits of the input and B to the last 64 bits of the input. Yes, they
+    // will overlap in the middle if we are working with less than the full 16
     // bytes.
     a = y_absl::base_internal::UnalignedLoad64(ptr);
     b = y_absl::base_internal::UnalignedLoad64(ptr + len - 8);
@@ -97,20 +135,14 @@ uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed,
     // bits and B to the last 32 bits.
     a = y_absl::base_internal::UnalignedLoad32(ptr);
     b = y_absl::base_internal::UnalignedLoad32(ptr + len - 4);
-  } else if (len > 0) {
-    // If we have at least 1 and at most 3 bytes, read all of the provided
-    // bits into A, with some adjustments.
-    a = static_cast<uint64_t>((ptr[0] << 16) | (ptr[len >> 1] << 8) |
-                              ptr[len - 1]);
-    b = 0;
   } else {
-    a = 0;
-    b = 0;
+    // If we have at least 1 and at most 3 bytes, read 2 bytes into A and the
+    // other byte into B, with some adjustments.
+    a = static_cast<uint64_t>((ptr[0] << 8) | ptr[len - 1]);
+    b = static_cast<uint64_t>(ptr[len >> 1]);
   }
 
-  uint64_t w = Mix(a ^ salt[1], b ^ current_state);
-  uint64_t z = salt[1] ^ starting_length;
-  return Mix(w, z);
+  return Mix(a ^ salt[1] ^ starting_length, b ^ current_state);
 }
 
 }  // namespace hash_internal
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.h b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.h
index f371e59433..e55e857188 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/hash/internal/low_level_hash.h
@@ -43,6 +43,10 @@ namespace hash_internal {
 uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed,
                       const uint64_t salt[5]);
 
+// Same as above except the length must be greater than 16.
+uint64_t LowLevelHashLenGt16(const void* data, size_t len, uint64_t seed,
+                             const uint64_t salt[5]);
+
 }  // namespace hash_internal
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/memory/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/memory/ya.make
index d1894c43e5..9e45a8300e 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/memory/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/memory/ya.make
@@ -6,9 +6,9 @@ LICENSE(Apache-2.0)
 
 LICENSE_TEXTS(.yandex_meta/licenses.list.txt)
 
-VERSION(20240116.2)
+VERSION(20240722.0)
 
-ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240116.2.tar.gz)
+ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz)
 
 PEERDIR(
     contrib/restricted/abseil-cpp-tstring/y_absl/meta
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/meta/type_traits.h b/contrib/restricted/abseil-cpp-tstring/y_absl/meta/type_traits.h
index 0bec59b056..b05179217b 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/meta/type_traits.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/meta/type_traits.h
@@ -37,11 +37,21 @@
 
 #include <cstddef>
 #include <functional>
+#include <util/generic/string.h>
 #include <type_traits>
+#include <vector>
 
 #include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 
+#ifdef __cpp_lib_span
+#include <span>  // NOLINT(build/c++20)
+#endif
+
+#ifdef Y_ABSL_HAVE_STD_STRING_VIEW
+#include <string_view>
+#endif
+
 // Defines the default alignment. `__STDCPP_DEFAULT_NEW_ALIGNMENT__` is a C++17
 // feature.
 #if defined(__STDCPP_DEFAULT_NEW_ALIGNMENT__)
@@ -152,8 +162,8 @@ template <typename... Ts>
 struct disjunction : std::false_type {};
 
 template <typename T, typename... Ts>
-struct disjunction<T, Ts...> :
-      std::conditional<T::value, T, disjunction<Ts...>>::type {};
+struct disjunction<T, Ts...>
+    : std::conditional<T::value, T, disjunction<Ts...>>::type {};
 
 template <typename T>
 struct disjunction<T> : T {};
@@ -279,27 +289,6 @@ using remove_extent_t = typename std::remove_extent<T>::type;
 template <typename T>
 using remove_all_extents_t = typename std::remove_all_extents<T>::type;
 
-Y_ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
-namespace type_traits_internal {
-// This trick to retrieve a default alignment is necessary for our
-// implementation of aligned_storage_t to be consistent with any
-// implementation of std::aligned_storage.
-template <size_t Len, typename T = std::aligned_storage<Len>>
-struct default_alignment_of_aligned_storage;
-
-template <size_t Len, size_t Align>
-struct default_alignment_of_aligned_storage<
-    Len, std::aligned_storage<Len, Align>> {
-  static constexpr size_t value = Align;
-};
-}  // namespace type_traits_internal
-
-// TODO(b/260219225): std::aligned_storage(_t) is deprecated in C++23.
-template <size_t Len, size_t Align = type_traits_internal::
-                          default_alignment_of_aligned_storage<Len>::value>
-using aligned_storage_t = typename std::aligned_storage<Len, Align>::type;
-Y_ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
-
 template <typename T>
 using decay_t = typename std::decay<T>::type;
 
@@ -315,22 +304,23 @@ using common_type_t = typename std::common_type<T...>::type;
 template <typename T>
 using underlying_type_t = typename std::underlying_type<T>::type;
 
-
 namespace type_traits_internal {
 
 #if (defined(__cpp_lib_is_invocable) && __cpp_lib_is_invocable >= 201703L) || \
     (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
 // std::result_of is deprecated (C++17) or removed (C++20)
-template<typename> struct result_of;
-template<typename F, typename... Args>
+template <typename>
+struct result_of;
+template <typename F, typename... Args>
 struct result_of<F(Args...)> : std::invoke_result<F, Args...> {};
 #else
-template<typename F> using result_of = std::result_of<F>;
+template <typename F>
+using result_of = std::result_of<F>;
 #endif
 
 }  // namespace type_traits_internal
 
-template<typename F>
+template <typename F>
 using result_of_t = typename type_traits_internal::result_of<F>::type;
 
 namespace type_traits_internal {
@@ -463,20 +453,23 @@ namespace type_traits_internal {
 // Make the swap-related traits/function accessible from this namespace.
 using swap_internal::IsNothrowSwappable;
 using swap_internal::IsSwappable;
-using swap_internal::Swap;
 using swap_internal::StdSwapIsUnconstrained;
+using swap_internal::Swap;
 
 }  // namespace type_traits_internal
 
 // y_absl::is_trivially_relocatable<T>
 //
 // Detects whether a type is known to be "trivially relocatable" -- meaning it
-// can be relocated without invoking the constructor/destructor, using a form of
-// move elision.
+// can be relocated from one place to another as if by memcpy/memmove.
+// This implies that its object representation doesn't depend on its address,
+// and also none of its special member functions do anything strange.
 //
-// This trait is conservative, for backwards compatibility. If it's true then
-// the type is definitely trivially relocatable, but if it's false then the type
-// may or may not be.
+// This trait is conservative. If it's true then the type is definitely
+// trivially relocatable, but if it's false then the type may or may not be. For
+// example, std::vector<int> is trivially relocatable on every known STL
+// implementation, but y_absl::is_trivially_relocatable<std::vector<int>> remains
+// false.
 //
 // Example:
 //
@@ -501,22 +494,34 @@ using swap_internal::StdSwapIsUnconstrained;
 //
 // TODO(b/275003464): remove the opt-out once the bug is fixed.
 //
+// Starting with Xcode 15, the Apple compiler will falsely say a type
+// with a user-provided move constructor is trivially relocatable
+// (b/324278148). We will opt out without a version check, due to
+// the fluidity of Apple versions.
+//
+// TODO(b/324278148): If all versions we use have the bug fixed, then
+// remove the condition.
+//
+// Clang on all platforms fails to detect that a type with a user-provided
+// move-assignment operator is not trivially relocatable. So in fact we
+// opt out of Clang altogether, for now.
+//
+// TODO(b/325479096): Remove the opt-out once Clang's behavior is fixed.
+//
 // According to https://github.com/abseil/abseil-cpp/issues/1479, this does not
 // work with NVCC either.
-#if Y_ABSL_HAVE_BUILTIN(__is_trivially_relocatable) &&                 \
-    !(defined(__clang__) && (defined(_WIN32) || defined(_WIN64))) && \
-    !defined(__NVCC__)
+#if Y_ABSL_HAVE_BUILTIN(__is_trivially_relocatable) && \
+    (defined(__cpp_impl_trivially_relocatable) ||    \
+     (!defined(__clang__) && !defined(__APPLE__) && !defined(__NVCC__)))
 template <class T>
 struct is_trivially_relocatable
     : std::integral_constant<bool, __is_trivially_relocatable(T)> {};
 #else
 // Otherwise we use a fallback that detects only those types we can feasibly
-// detect. Any time that has trivial move-construction and destruction
-// operations is by definition trivially relocatable.
+// detect. Any type that is trivially copyable is by definition trivially
+// relocatable.
 template <class T>
-struct is_trivially_relocatable
-    : y_absl::conjunction<y_absl::is_trivially_move_constructible<T>,
-                        y_absl::is_trivially_destructible<T>> {};
+struct is_trivially_relocatable : std::is_trivially_copyable<T> {};
 #endif
 
 // y_absl::is_constant_evaluated()
@@ -558,6 +563,97 @@ constexpr bool is_constant_evaluated() noexcept {
 #endif
 }
 #endif  // Y_ABSL_HAVE_CONSTANT_EVALUATED
+
+namespace type_traits_internal {
+
+// Detects if a class's definition has declared itself to be an owner by
+// declaring
+//   using absl_internal_is_view = std::true_type;
+// as a member.
+// Types that don't want either must either omit this declaration entirely, or
+// (if e.g. inheriting from a base class) define the member to something that
+// isn't a Boolean trait class, such as `void`.
+// Do not specialize or use this directly. It's an implementation detail.
+template <typename T, typename = void>
+struct IsOwnerImpl : std::false_type {
+  static_assert(std::is_same<T, y_absl::remove_cvref_t<T>>::value,
+                "type must lack qualifiers");
+};
+
+template <typename T>
+struct IsOwnerImpl<
+    T,
+    std::enable_if_t<std::is_class<typename T::absl_internal_is_view>::value>>
+    : y_absl::negation<typename T::absl_internal_is_view> {};
+
+// A trait to determine whether a type is an owner.
+// Do *not* depend on the correctness of this trait for correct code behavior.
+// It is only a safety feature and its value may change in the future.
+// Do not specialize this; instead, define the member trait inside your type so
+// that it can be auto-detected, and to prevent ODR violations.
+// If it ever becomes possible to detect [[gsl::Owner]], we should leverage it:
+// https://wg21.link/p1179
+template <typename T>
+struct IsOwner : IsOwnerImpl<T> {};
+
+template <typename T, typename Traits, typename Alloc>
+struct IsOwner<std::basic_string<T, Traits, Alloc>> : std::true_type {};
+
+template <typename T, typename Alloc>
+struct IsOwner<std::vector<T, Alloc>> : std::true_type {};
+
+// Detects if a class's definition has declared itself to be a view by declaring
+//   using absl_internal_is_view = std::true_type;
+// as a member.
+// Do not specialize or use this directly.
+template <typename T, typename = void>
+struct IsViewImpl : std::false_type {
+  static_assert(std::is_same<T, y_absl::remove_cvref_t<T>>::value,
+                "type must lack qualifiers");
+};
+
+template <typename T>
+struct IsViewImpl<
+    T,
+    std::enable_if_t<std::is_class<typename T::absl_internal_is_view>::value>>
+    : T::absl_internal_is_view {};
+
+// A trait to determine whether a type is a view.
+// Do *not* depend on the correctness of this trait for correct code behavior.
+// It is only a safety feature, and its value may change in the future.
+// Do not specialize this trait. Instead, define the member
+//   using absl_internal_is_view = std::true_type;
+// in your class to allow its detection while preventing ODR violations.
+// If it ever becomes possible to detect [[gsl::Pointer]], we should leverage
+// it: https://wg21.link/p1179
+template <typename T>
+struct IsView : std::integral_constant<bool, std::is_pointer<T>::value ||
+                                                 IsViewImpl<T>::value> {};
+
+#ifdef Y_ABSL_HAVE_STD_STRING_VIEW
+template <typename Char, typename Traits>
+struct IsView<std::basic_string_view<Char, Traits>> : std::true_type {};
+#endif
+
+#ifdef __cpp_lib_span
+template <typename T>
+struct IsView<std::span<T>> : std::true_type {};
+#endif
+
+// Determines whether the assignment of the given types is lifetime-bound.
+// Do *not* depend on the correctness of this trait for correct code behavior.
+// It is only a safety feature and its value may change in the future.
+// If it ever becomes possible to detect [[clang::lifetimebound]] directly,
+// we should change the implementation to leverage that.
+// Until then, we consider an assignment from an "owner" (such as TString)
+// to a "view" (such as std::string_view) to be a lifetime-bound assignment.
+template <typename T, typename U>
+using IsLifetimeBoundAssignment =
+    std::integral_constant<bool, IsView<y_absl::remove_cvref_t<T>>::value &&
+                                     IsOwner<y_absl::remove_cvref_t<U>>::value>;
+
+}  // namespace type_traits_internal
+
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/meta/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/meta/ya.make
index 1b4070658f..e91c314898 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/meta/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/meta/ya.make
@@ -6,9 +6,9 @@ LICENSE(Apache-2.0)
 
 LICENSE_TEXTS(.yandex_meta/licenses.list.txt)
 
-VERSION(20240116.2)
+VERSION(20240722.0)
 
-ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240116.2.tar.gz)
+ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz)
 
 PEERDIR(
     contrib/restricted/abseil-cpp-tstring/y_absl/base
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.cc
index fa62f6ad50..c57010c4c1 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.cc
@@ -29,9 +29,6 @@
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
 
-Y_ABSL_DLL const uint128 kuint128max = MakeUint128(
-    std::numeric_limits<uint64_t>::max(), std::numeric_limits<uint64_t>::max());
-
 namespace {
 
 // Returns the 0-based position of the last set bit (i.e., most significant bit)
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.h b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.h
index d90efdaece..92d90e482d 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128.h
@@ -38,6 +38,7 @@
 #include "y_absl/base/config.h"
 #include "y_absl/base/macros.h"
 #include "y_absl/base/port.h"
+#include "y_absl/types/compare.h"
 
 #if defined(_MSC_VER)
 // In very old versions of MSVC and when the /Zc:wchar_t flag is off, wchar_t is
@@ -244,11 +245,6 @@ class
 #endif  // byte order
 };
 
-// Prefer to use the constexpr `Uint128Max()`.
-//
-// TODO(y_absl-team) deprecate kuint128max once migration tool is released.
-Y_ABSL_DLL extern const uint128 kuint128max;
-
 // allow uint128 to be logged
 std::ostream& operator<<(std::ostream& os, uint128 v);
 
@@ -274,7 +270,9 @@ class numeric_limits<y_absl::uint128> {
   static constexpr bool has_infinity = false;
   static constexpr bool has_quiet_NaN = false;
   static constexpr bool has_signaling_NaN = false;
+  Y_ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
   static constexpr float_denorm_style has_denorm = denorm_absent;
+  Y_ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
   static constexpr bool has_denorm_loss = false;
   static constexpr float_round_style round_style = round_toward_zero;
   static constexpr bool is_iec559 = false;
@@ -517,7 +515,9 @@ class numeric_limits<y_absl::int128> {
   static constexpr bool has_infinity = false;
   static constexpr bool has_quiet_NaN = false;
   static constexpr bool has_signaling_NaN = false;
+  Y_ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
   static constexpr float_denorm_style has_denorm = denorm_absent;
+  Y_ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
   static constexpr bool has_denorm_loss = false;
   static constexpr float_round_style round_style = round_toward_zero;
   static constexpr bool is_iec559 = false;
@@ -824,6 +824,36 @@ constexpr bool operator<=(uint128 lhs, uint128 rhs) { return !(rhs < lhs); }
 
 constexpr bool operator>=(uint128 lhs, uint128 rhs) { return !(lhs < rhs); }
 
+#ifdef __cpp_impl_three_way_comparison
+constexpr y_absl::strong_ordering operator<=>(uint128 lhs, uint128 rhs) {
+#if defined(Y_ABSL_HAVE_INTRINSIC_INT128)
+  if (auto lhs_128 = static_cast<unsigned __int128>(lhs),
+      rhs_128 = static_cast<unsigned __int128>(rhs);
+      lhs_128 < rhs_128) {
+    return y_absl::strong_ordering::less;
+  } else if (lhs_128 > rhs_128) {
+    return y_absl::strong_ordering::greater;
+  } else {
+    return y_absl::strong_ordering::equal;
+  }
+#else
+  if (uint64_t lhs_high = Uint128High64(lhs), rhs_high = Uint128High64(rhs);
+      lhs_high < rhs_high) {
+    return y_absl::strong_ordering::less;
+  } else if (lhs_high > rhs_high) {
+    return y_absl::strong_ordering::greater;
+  } else if (uint64_t lhs_low = Uint128Low64(lhs), rhs_low = Uint128Low64(rhs);
+             lhs_low < rhs_low) {
+    return y_absl::strong_ordering::less;
+  } else if (lhs_low > rhs_low) {
+    return y_absl::strong_ordering::greater;
+  } else {
+    return y_absl::strong_ordering::equal;
+  }
+#endif
+}
+#endif
+
 // Unary operators.
 
 constexpr inline uint128 operator+(uint128 val) { return val; }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_have_intrinsic.inc b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_have_intrinsic.inc
index 7133611d8f..19f83d1ae4 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_have_intrinsic.inc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_have_intrinsic.inc
@@ -220,6 +220,20 @@ constexpr bool operator>=(int128 lhs, int128 rhs) {
   return static_cast<__int128>(lhs) >= static_cast<__int128>(rhs);
 }
 
+#ifdef __cpp_impl_three_way_comparison
+constexpr y_absl::strong_ordering operator<=>(int128 lhs, int128 rhs) {
+  if (auto lhs_128 = static_cast<__int128>(lhs),
+      rhs_128 = static_cast<__int128>(rhs);
+      lhs_128 < rhs_128) {
+    return y_absl::strong_ordering::less;
+  } else if (lhs_128 > rhs_128) {
+    return y_absl::strong_ordering::greater;
+  } else {
+    return y_absl::strong_ordering::equal;
+  }
+}
+#endif
+
 // Unary operators.
 
 constexpr int128 operator-(int128 v) { return -static_cast<__int128>(v); }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_no_intrinsic.inc b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_no_intrinsic.inc
index e41d2a55e6..836cef3213 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_no_intrinsic.inc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/int128_no_intrinsic.inc
@@ -186,6 +186,24 @@ constexpr bool operator<=(int128 lhs, int128 rhs) { return !(lhs > rhs); }
 
 constexpr bool operator>=(int128 lhs, int128 rhs) { return !(lhs < rhs); }
 
+#ifdef __cpp_impl_three_way_comparison
+constexpr y_absl::strong_ordering operator<=>(int128 lhs, int128 rhs) {
+  if (int64_t lhs_high = Int128High64(lhs), rhs_high = Int128High64(rhs);
+      lhs_high < rhs_high) {
+    return y_absl::strong_ordering::less;
+  } else if (lhs_high > rhs_high) {
+    return y_absl::strong_ordering::greater;
+  } else if (uint64_t lhs_low = Uint128Low64(lhs), rhs_low = Uint128Low64(rhs);
+             lhs_low < rhs_low) {
+    return y_absl::strong_ordering::less;
+  } else if (lhs_low > rhs_low) {
+    return y_absl::strong_ordering::greater;
+  } else {
+    return y_absl::strong_ordering::equal;
+  }
+}
+#endif
+
 // Unary operators.
 
 constexpr int128 operator-(int128 v) {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/internal/bits.h b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/internal/bits.h
index a19e3c6bbc..152b5005a3 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/internal/bits.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/numeric/internal/bits.h
@@ -167,7 +167,9 @@ CountLeadingZeroes32(uint32_t x) {
 
 Y_ABSL_ATTRIBUTE_ALWAYS_INLINE Y_ABSL_INTERNAL_CONSTEXPR_CLZ inline int
 CountLeadingZeroes16(uint16_t x) {
-#if Y_ABSL_HAVE_BUILTIN(__builtin_clzs)
+#if Y_ABSL_HAVE_BUILTIN(__builtin_clzg)
+  return x == 0 ? 16 : __builtin_clzg(x);
+#elif Y_ABSL_HAVE_BUILTIN(__builtin_clzs)
   static_assert(sizeof(unsigned short) == sizeof(x),  // NOLINT(runtime/int)
                 "__builtin_clzs does not take 16-bit arg");
   return x == 0 ? 16 : __builtin_clzs(x);
@@ -303,7 +305,9 @@ CountTrailingZeroesNonzero64(uint64_t x) {
 
 Y_ABSL_ATTRIBUTE_ALWAYS_INLINE Y_ABSL_INTERNAL_CONSTEXPR_CTZ inline int
 CountTrailingZeroesNonzero16(uint16_t x) {
-#if Y_ABSL_HAVE_BUILTIN(__builtin_ctzs)
+#if Y_ABSL_HAVE_BUILTIN(__builtin_ctzg)
+  return __builtin_ctzg(x);
+#elif Y_ABSL_HAVE_BUILTIN(__builtin_ctzs)
   static_assert(sizeof(unsigned short) == sizeof(x),  // NOLINT(runtime/int)
                 "__builtin_ctzs does not take 16-bit arg");
   return __builtin_ctzs(x);
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/profiling/internal/periodic_sampler.h b/contrib/restricted/abseil-cpp-tstring/y_absl/profiling/internal/periodic_sampler.h
index 6faa2d7566..ada284be0b 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/profiling/internal/periodic_sampler.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/profiling/internal/periodic_sampler.h
@@ -172,7 +172,7 @@ inline bool PeriodicSamplerBase::Sample() noexcept {
 // Typical use case:
 //
 //   struct HashTablezTag {};
-//   thread_local PeriodicSampler sampler;
+//   thread_local PeriodicSampler<HashTablezTag, 100> sampler;
 //
 //   void HashTableSamplingLogic(...) {
 //     if (sampler.Sample()) {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/random/beta_distribution.h b/contrib/restricted/abseil-cpp-tstring/y_absl/random/beta_distribution.h
index 8914a8b45a..b0a336d3d4 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/random/beta_distribution.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/random/beta_distribution.h
@@ -181,18 +181,18 @@ class beta_distribution {
     result_type alpha_;
     result_type beta_;
 
-    result_type a_;  // the smaller of {alpha, beta}, or 1.0/alpha_ in JOEHNK
-    result_type b_;  // the larger of {alpha, beta}, or 1.0/beta_ in JOEHNK
-    result_type x_;  // alpha + beta, or the result in degenerate cases
-    result_type log_x_;  // log(x_)
-    result_type y_;      // "beta" in Cheng
-    result_type gamma_;  // "gamma" in Cheng
+    result_type a_{};  // the smaller of {alpha, beta}, or 1.0/alpha_ in JOEHNK
+    result_type b_{};  // the larger of {alpha, beta}, or 1.0/beta_ in JOEHNK
+    result_type x_{};  // alpha + beta, or the result in degenerate cases
+    result_type log_x_{};  // log(x_)
+    result_type y_{};      // "beta" in Cheng
+    result_type gamma_{};  // "gamma" in Cheng
 
-    Method method_;
+    Method method_{};
 
     // Placing this last for optimal alignment.
     // Whether alpha_ != a_, i.e. true iff alpha_ > beta_.
-    bool inverted_;
+    bool inverted_{};
 
     static_assert(std::is_floating_point<RealType>::value,
                   "Class-template y_absl::beta_distribution<> must be "
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/random/distributions.h b/contrib/restricted/abseil-cpp-tstring/y_absl/random/distributions.h
index ddd1b9ce6e..84a13b47df 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/random/distributions.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/random/distributions.h
@@ -32,8 +32,8 @@
 //     continuously and independently at a constant average rate
 //   * `y_absl::Gaussian` (also known as "normal distributions") for continuous
 //     distributions using an associated quadratic function
-//   * `y_absl::LogUniform` for continuous uniform distributions where the log
-//     to the given base of all values is uniform
+//   * `y_absl::LogUniform` for discrete distributions where the log to the given
+//     base of all values is uniform
 //   * `y_absl::Poisson` for discrete probability distributions that express the
 //     probability of a given number of events occurring within a fixed interval
 //   * `y_absl::Zipf` for discrete probability distributions commonly used for
@@ -46,23 +46,23 @@
 #ifndef Y_ABSL_RANDOM_DISTRIBUTIONS_H_
 #define Y_ABSL_RANDOM_DISTRIBUTIONS_H_
 
-#include <algorithm>
-#include <cmath>
 #include <limits>
-#include <random>
 #include <type_traits>
 
+#include "y_absl/base/config.h"
 #include "y_absl/base/internal/inline_variable.h"
+#include "y_absl/meta/type_traits.h"
 #include "y_absl/random/bernoulli_distribution.h"
 #include "y_absl/random/beta_distribution.h"
 #include "y_absl/random/exponential_distribution.h"
 #include "y_absl/random/gaussian_distribution.h"
 #include "y_absl/random/internal/distribution_caller.h"  // IWYU pragma: export
+#include "y_absl/random/internal/traits.h"
 #include "y_absl/random/internal/uniform_helper.h"  // IWYU pragma: export
 #include "y_absl/random/log_uniform_int_distribution.h"
 #include "y_absl/random/poisson_distribution.h"
-#include "y_absl/random/uniform_int_distribution.h"
-#include "y_absl/random/uniform_real_distribution.h"
+#include "y_absl/random/uniform_int_distribution.h"  // IWYU pragma: export
+#include "y_absl/random/uniform_real_distribution.h"  // IWYU pragma: export
 #include "y_absl/random/zipf_distribution.h"
 
 namespace y_absl {
@@ -176,7 +176,7 @@ Uniform(TagType tag,
 
   return random_internal::DistributionCaller<gen_t>::template Call<
       distribution_t>(&urbg, tag, static_cast<return_t>(lo),
-                                static_cast<return_t>(hi));
+                      static_cast<return_t>(hi));
 }
 
 // y_absl::Uniform(bitgen, lo, hi)
@@ -200,7 +200,7 @@ Uniform(URBG&& urbg,  // NOLINT(runtime/references)
 
   return random_internal::DistributionCaller<gen_t>::template Call<
       distribution_t>(&urbg, static_cast<return_t>(lo),
-                                static_cast<return_t>(hi));
+                      static_cast<return_t>(hi));
 }
 
 // y_absl::Uniform<unsigned T>(bitgen)
@@ -208,7 +208,7 @@ Uniform(URBG&& urbg,  // NOLINT(runtime/references)
 // Overload of Uniform() using the minimum and maximum values of a given type
 // `T` (which must be unsigned), returning a value of type `unsigned T`
 template <typename R, typename URBG>
-typename y_absl::enable_if_t<!std::is_signed<R>::value, R>  //
+typename y_absl::enable_if_t<!std::numeric_limits<R>::is_signed, R>  //
 Uniform(URBG&& urbg) {  // NOLINT(runtime/references)
   using gen_t = y_absl::decay_t<URBG>;
   using distribution_t = random_internal::UniformDistributionWrapper<R>;
@@ -362,7 +362,7 @@ RealType Gaussian(URBG&& urbg,  // NOLINT(runtime/references)
 // If `lo` is nonzero then this distribution is shifted to the desired interval,
 // so LogUniform(lo, hi, b) is equivalent to LogUniform(0, hi-lo, b)+lo.
 //
-// See https://en.wikipedia.org/wiki/Log-normal_distribution
+// See https://en.wikipedia.org/wiki/Reciprocal_distribution
 //
 // Example:
 //
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/random/seed_sequences.h b/contrib/restricted/abseil-cpp-tstring/y_absl/random/seed_sequences.h
index c5bd44e13f..de4f71c25e 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/random/seed_sequences.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/random/seed_sequences.h
@@ -29,9 +29,11 @@
 #include <random>
 
 #include "y_absl/base/config.h"
+#include "y_absl/base/nullability.h"
 #include "y_absl/random/internal/salted_seed_seq.h"
 #include "y_absl/random/internal/seed_material.h"
 #include "y_absl/random/seed_gen_exception.h"
+#include "y_absl/strings/string_view.h"
 #include "y_absl/types/span.h"
 
 namespace y_absl {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/status/internal/statusor_internal.h b/contrib/restricted/abseil-cpp-tstring/y_absl/status/internal/statusor_internal.h
index fa22190dbd..5fd4edf791 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/status/internal/statusor_internal.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/status/internal/statusor_internal.h
@@ -123,11 +123,70 @@ using IsForwardingAssignmentValid = y_absl::disjunction<
         std::is_same<y_absl::in_place_t, y_absl::remove_cvref_t<U>>,
         IsForwardingAssignmentAmbiguous<T, U>>>>;
 
+template <bool Value, typename T>
+using Equality = std::conditional_t<Value, T, y_absl::negation<T>>;
+
+template <bool Explicit, typename T, typename U, bool Lifetimebound>
+using IsConstructionValid = y_absl::conjunction<
+    Equality<Lifetimebound,
+             type_traits_internal::IsLifetimeBoundAssignment<T, U>>,
+    IsDirectInitializationValid<T, U&&>, std::is_constructible<T, U&&>,
+    Equality<!Explicit, std::is_convertible<U&&, T>>,
+    y_absl::disjunction<
+        std::is_same<T, y_absl::remove_cvref_t<U>>,
+        y_absl::conjunction<
+            std::conditional_t<
+                Explicit,
+                y_absl::negation<std::is_constructible<y_absl::Status, U&&>>,
+                y_absl::negation<std::is_convertible<U&&, y_absl::Status>>>,
+            y_absl::negation<
+                internal_statusor::HasConversionOperatorToStatusOr<T, U&&>>>>>;
+
+template <typename T, typename U, bool Lifetimebound>
+using IsAssignmentValid = y_absl::conjunction<
+    Equality<Lifetimebound,
+             type_traits_internal::IsLifetimeBoundAssignment<T, U>>,
+    std::is_constructible<T, U&&>, std::is_assignable<T&, U&&>,
+    y_absl::disjunction<
+        std::is_same<T, y_absl::remove_cvref_t<U>>,
+        y_absl::conjunction<
+            y_absl::negation<std::is_convertible<U&&, y_absl::Status>>,
+            y_absl::negation<HasConversionOperatorToStatusOr<T, U&&>>>>,
+    IsForwardingAssignmentValid<T, U&&>>;
+
+template <bool Explicit, typename T, typename U>
+using IsConstructionFromStatusValid = y_absl::conjunction<
+    y_absl::negation<std::is_same<y_absl::StatusOr<T>, y_absl::remove_cvref_t<U>>>,
+    y_absl::negation<std::is_same<T, y_absl::remove_cvref_t<U>>>,
+    y_absl::negation<std::is_same<y_absl::in_place_t, y_absl::remove_cvref_t<U>>>,
+    Equality<!Explicit, std::is_convertible<U, y_absl::Status>>,
+    std::is_constructible<y_absl::Status, U>,
+    y_absl::negation<HasConversionOperatorToStatusOr<T, U>>>;
+
+template <bool Explicit, typename T, typename U, bool Lifetimebound,
+          typename UQ>
+using IsConstructionFromStatusOrValid = y_absl::conjunction<
+    y_absl::negation<std::is_same<T, U>>,
+    Equality<Lifetimebound,
+             type_traits_internal::IsLifetimeBoundAssignment<T, U>>,
+    std::is_constructible<T, UQ>,
+    Equality<!Explicit, std::is_convertible<UQ, T>>,
+    y_absl::negation<IsConstructibleOrConvertibleFromStatusOr<T, U>>>;
+
+template <typename T, typename U, bool Lifetimebound>
+using IsStatusOrAssignmentValid = y_absl::conjunction<
+    y_absl::negation<std::is_same<T, y_absl::remove_cvref_t<U>>>,
+    Equality<Lifetimebound,
+             type_traits_internal::IsLifetimeBoundAssignment<T, U>>,
+    std::is_constructible<T, U>, std::is_assignable<T, U>,
+    y_absl::negation<IsConstructibleOrConvertibleOrAssignableFromStatusOr<
+        T, y_absl::remove_cvref_t<U>>>>;
+
 class Helper {
  public:
   // Move type-agnostic error handling to the .cc.
   static void HandleInvalidStatusCtorArg(y_absl::Nonnull<Status*>);
-  Y_ABSL_ATTRIBUTE_NORETURN static void Crash(const y_absl::Status& status);
+  [[noreturn]] static void Crash(const y_absl::Status& status);
 };
 
 // Construct an instance of T in `p` through placement new, passing Args... to
@@ -379,7 +438,7 @@ struct MoveAssignBase<T, false> {
   MoveAssignBase& operator=(MoveAssignBase&&) = delete;
 };
 
-Y_ABSL_ATTRIBUTE_NORETURN void ThrowBadStatusOrAccess(y_absl::Status status);
+[[noreturn]] void ThrowBadStatusOrAccess(y_absl::Status status);
 
 // Used to introduce jitter into the output of printing functions for
 // `StatusOr` (i.e. `AbslStringify` and `operator<<`).
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.cc
index 41655b15e2..25098c1593 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.cc
@@ -273,14 +273,12 @@ StatusCode ErrnoToStatusCode(int error_number) {
     case EFAULT:        // Bad address
     case EILSEQ:        // Illegal byte sequence
     case ENOPROTOOPT:   // Protocol not available
-    case ENOSTR:        // Not a STREAM
     case ENOTSOCK:      // Not a socket
     case ENOTTY:        // Inappropriate I/O control operation
     case EPROTOTYPE:    // Protocol wrong type for socket
     case ESPIPE:        // Invalid seek
       return StatusCode::kInvalidArgument;
     case ETIMEDOUT:  // Connection timed out
-    case ETIME:      // Timer expired
       return StatusCode::kDeadlineExceeded;
     case ENODEV:  // No such device
     case ENOENT:  // No such file or directory
@@ -339,9 +337,7 @@ StatusCode ErrnoToStatusCode(int error_number) {
     case EMLINK:   // Too many links
     case ENFILE:   // Too many open files in system
     case ENOBUFS:  // No buffer space available
-    case ENODATA:  // No message is available on the STREAM read queue
     case ENOMEM:   // Not enough space
-    case ENOSR:    // No STREAM resources
 #ifdef EUSERS
     case EUSERS:  // Too many users
 #endif
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.h b/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.h
index d2d9d3742b..6fdf608b2a 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/status/status.h
@@ -452,7 +452,7 @@ class Y_ABSL_ATTRIBUTE_TRIVIAL_ABI Status final {
 
   // The moved-from state is valid but unspecified.
   Status(Status&&) noexcept;
-  Status& operator=(Status&&);
+  Status& operator=(Status&&) noexcept;
 
   ~Status();
 
@@ -539,7 +539,7 @@ class Y_ABSL_ATTRIBUTE_TRIVIAL_ABI Status final {
   // swap()
   //
   // Swap the contents of one status with another.
-  friend void swap(Status& a, Status& b);
+  friend void swap(Status& a, Status& b) noexcept;
 
   //----------------------------------------------------------------------------
   // Payload Management APIs
@@ -789,7 +789,7 @@ inline Status::Status(Status&& x) noexcept : Status(x.rep_) {
   x.rep_ = MovedFromRep();
 }
 
-inline Status& Status::operator=(Status&& x) {
+inline Status& Status::operator=(Status&& x) noexcept {
   uintptr_t old_rep = rep_;
   if (x.rep_ != old_rep) {
     rep_ = x.rep_;
@@ -852,7 +852,7 @@ inline void Status::IgnoreError() const {
   // no-op
 }
 
-inline void swap(y_absl::Status& a, y_absl::Status& b) {
+inline void swap(y_absl::Status& a, y_absl::Status& b) noexcept {
   using std::swap;
   swap(a.rep_, b.rep_);
 }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/status/statusor.h b/contrib/restricted/abseil-cpp-tstring/y_absl/status/statusor.h
index d12ed41d15..dd6462f691 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/status/statusor.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/status/statusor.h
@@ -236,57 +236,55 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
   // is explicit if and only if the corresponding construction of `T` from `U`
   // is explicit. (This constructor inherits its explicitness from the
   // underlying constructor.)
-  template <
-      typename U,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_same<T, U>>,
-              std::is_constructible<T, const U&>,
-              std::is_convertible<const U&, T>,
-              y_absl::negation<
-                  internal_statusor::IsConstructibleOrConvertibleFromStatusOr<
-                      T, U>>>::value,
-          int> = 0>
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                false, T, U, false, const U&>::value,
+                            int> = 0>
   StatusOr(const StatusOr<U>& other)  // NOLINT
       : Base(static_cast<const typename StatusOr<U>::Base&>(other)) {}
-  template <
-      typename U,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_same<T, U>>,
-              std::is_constructible<T, const U&>,
-              y_absl::negation<std::is_convertible<const U&, T>>,
-              y_absl::negation<
-                  internal_statusor::IsConstructibleOrConvertibleFromStatusOr<
-                      T, U>>>::value,
-          int> = 0>
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                false, T, U, true, const U&>::value,
+                            int> = 0>
+  StatusOr(const StatusOr<U>& other Y_ABSL_ATTRIBUTE_LIFETIME_BOUND)  // NOLINT
+      : Base(static_cast<const typename StatusOr<U>::Base&>(other)) {}
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                true, T, U, false, const U&>::value,
+                            int> = 0>
   explicit StatusOr(const StatusOr<U>& other)
       : Base(static_cast<const typename StatusOr<U>::Base&>(other)) {}
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                true, T, U, true, const U&>::value,
+                            int> = 0>
+  explicit StatusOr(const StatusOr<U>& other Y_ABSL_ATTRIBUTE_LIFETIME_BOUND)
+      : Base(static_cast<const typename StatusOr<U>::Base&>(other)) {}
 
-  template <
-      typename U,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_same<T, U>>, std::is_constructible<T, U&&>,
-              std::is_convertible<U&&, T>,
-              y_absl::negation<
-                  internal_statusor::IsConstructibleOrConvertibleFromStatusOr<
-                      T, U>>>::value,
-          int> = 0>
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                false, T, U, false, U&&>::value,
+                            int> = 0>
   StatusOr(StatusOr<U>&& other)  // NOLINT
       : Base(static_cast<typename StatusOr<U>::Base&&>(other)) {}
-  template <
-      typename U,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_same<T, U>>, std::is_constructible<T, U&&>,
-              y_absl::negation<std::is_convertible<U&&, T>>,
-              y_absl::negation<
-                  internal_statusor::IsConstructibleOrConvertibleFromStatusOr<
-                      T, U>>>::value,
-          int> = 0>
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                false, T, U, true, U&&>::value,
+                            int> = 0>
+  StatusOr(StatusOr<U>&& other Y_ABSL_ATTRIBUTE_LIFETIME_BOUND)  // NOLINT
+      : Base(static_cast<typename StatusOr<U>::Base&&>(other)) {}
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                true, T, U, false, U&&>::value,
+                            int> = 0>
   explicit StatusOr(StatusOr<U>&& other)
       : Base(static_cast<typename StatusOr<U>::Base&&>(other)) {}
+  template <typename U, y_absl::enable_if_t<
+                            internal_statusor::IsConstructionFromStatusOrValid<
+                                true, T, U, true, U&&>::value,
+                            int> = 0>
+  explicit StatusOr(StatusOr<U>&& other Y_ABSL_ATTRIBUTE_LIFETIME_BOUND)
+      : Base(static_cast<typename StatusOr<U>::Base&&>(other)) {}
 
   // Converting Assignment Operators
 
@@ -307,37 +305,38 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
   // These overloads only apply if `y_absl::StatusOr<T>` is constructible and
   // assignable from `y_absl::StatusOr<U>` and `StatusOr<T>` cannot be directly
   // assigned from `StatusOr<U>`.
-  template <
-      typename U,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_same<T, U>>,
-              std::is_constructible<T, const U&>,
-              std::is_assignable<T, const U&>,
-              y_absl::negation<
-                  internal_statusor::
-                      IsConstructibleOrConvertibleOrAssignableFromStatusOr<
-                          T, U>>>::value,
-          int> = 0>
+  template <typename U,
+            y_absl::enable_if_t<internal_statusor::IsStatusOrAssignmentValid<
+                                  T, const U&, false>::value,
+                              int> = 0>
   StatusOr& operator=(const StatusOr<U>& other) {
     this->Assign(other);
     return *this;
   }
-  template <
-      typename U,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_same<T, U>>, std::is_constructible<T, U&&>,
-              std::is_assignable<T, U&&>,
-              y_absl::negation<
-                  internal_statusor::
-                      IsConstructibleOrConvertibleOrAssignableFromStatusOr<
-                          T, U>>>::value,
-          int> = 0>
+  template <typename U,
+            y_absl::enable_if_t<internal_statusor::IsStatusOrAssignmentValid<
+                                  T, const U&, true>::value,
+                              int> = 0>
+  StatusOr& operator=(const StatusOr<U>& other Y_ABSL_ATTRIBUTE_LIFETIME_BOUND) {
+    this->Assign(other);
+    return *this;
+  }
+  template <typename U,
+            y_absl::enable_if_t<internal_statusor::IsStatusOrAssignmentValid<
+                                  T, U&&, false>::value,
+                              int> = 0>
   StatusOr& operator=(StatusOr<U>&& other) {
     this->Assign(std::move(other));
     return *this;
   }
+  template <typename U,
+            y_absl::enable_if_t<internal_statusor::IsStatusOrAssignmentValid<
+                                  T, U&&, true>::value,
+                              int> = 0>
+  StatusOr& operator=(StatusOr<U>&& other Y_ABSL_ATTRIBUTE_LIFETIME_BOUND) {
+    this->Assign(std::move(other));
+    return *this;
+  }
 
   // Constructs a new `y_absl::StatusOr<T>` with a non-ok status. After calling
   // this constructor, `this->ok()` will be `false` and calls to `value()` will
@@ -350,46 +349,21 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
   // REQUIRES: !Status(std::forward<U>(v)).ok(). This requirement is DCHECKed.
   // In optimized builds, passing y_absl::OkStatus() here will have the effect
   // of passing y_absl::StatusCode::kInternal as a fallback.
-  template <
-      typename U = y_absl::Status,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              std::is_convertible<U&&, y_absl::Status>,
-              std::is_constructible<y_absl::Status, U&&>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, y_absl::StatusOr<T>>>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, T>>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, y_absl::in_place_t>>,
-              y_absl::negation<internal_statusor::HasConversionOperatorToStatusOr<
-                  T, U&&>>>::value,
-          int> = 0>
+  template <typename U = y_absl::Status,
+            y_absl::enable_if_t<internal_statusor::IsConstructionFromStatusValid<
+                                  false, T, U>::value,
+                              int> = 0>
   StatusOr(U&& v) : Base(std::forward<U>(v)) {}
 
-  template <
-      typename U = y_absl::Status,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              y_absl::negation<std::is_convertible<U&&, y_absl::Status>>,
-              std::is_constructible<y_absl::Status, U&&>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, y_absl::StatusOr<T>>>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, T>>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, y_absl::in_place_t>>,
-              y_absl::negation<internal_statusor::HasConversionOperatorToStatusOr<
-                  T, U&&>>>::value,
-          int> = 0>
+  template <typename U = y_absl::Status,
+            y_absl::enable_if_t<internal_statusor::IsConstructionFromStatusValid<
+                                  true, T, U>::value,
+                              int> = 0>
   explicit StatusOr(U&& v) : Base(std::forward<U>(v)) {}
-
-  template <
-      typename U = y_absl::Status,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              std::is_convertible<U&&, y_absl::Status>,
-              std::is_constructible<y_absl::Status, U&&>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, y_absl::StatusOr<T>>>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, T>>,
-              y_absl::negation<std::is_same<y_absl::decay_t<U>, y_absl::in_place_t>>,
-              y_absl::negation<internal_statusor::HasConversionOperatorToStatusOr<
-                  T, U&&>>>::value,
-          int> = 0>
+  template <typename U = y_absl::Status,
+            y_absl::enable_if_t<internal_statusor::IsConstructionFromStatusValid<
+                                  false, T, U>::value,
+                              int> = 0>
   StatusOr& operator=(U&& v) {
     this->AssignStatus(std::forward<U>(v));
     return *this;
@@ -411,21 +385,22 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
   //    StatusOr<bool> s1 = true;  // s1.ok() && *s1 == true
   //    StatusOr<bool> s2 = false;  // s2.ok() && *s2 == false
   //    s1 = s2;  // ambiguous, `s1 = *s2` or `s1 = bool(s2)`?
-  template <
-      typename U = T,
-      typename = typename std::enable_if<y_absl::conjunction<
-          std::is_constructible<T, U&&>, std::is_assignable<T&, U&&>,
-          y_absl::disjunction<
-              std::is_same<y_absl::remove_cvref_t<U>, T>,
-              y_absl::conjunction<
-                  y_absl::negation<std::is_convertible<U&&, y_absl::Status>>,
-                  y_absl::negation<internal_statusor::
-                                     HasConversionOperatorToStatusOr<T, U&&>>>>,
-          internal_statusor::IsForwardingAssignmentValid<T, U&&>>::value>::type>
+  template <typename U = T,
+            typename std::enable_if<
+                internal_statusor::IsAssignmentValid<T, U, false>::value,
+                int>::type = 0>
   StatusOr& operator=(U&& v) {
     this->Assign(std::forward<U>(v));
     return *this;
   }
+  template <typename U = T,
+            typename std::enable_if<
+                internal_statusor::IsAssignmentValid<T, U, true>::value,
+                int>::type = 0>
+  StatusOr& operator=(U&& v Y_ABSL_ATTRIBUTE_LIFETIME_BOUND) {
+    this->Assign(std::forward<U>(v));
+    return *this;
+  }
 
   // Constructs the inner value `T` in-place using the provided args, using the
   // `T(args...)` constructor.
@@ -442,40 +417,31 @@ class StatusOr : private internal_statusor::StatusOrData<T>,
   // This constructor is explicit if `U` is not convertible to `T`. To avoid
   // ambiguity, this constructor is disabled if `U` is a `StatusOr<J>`, where
   // `J` is convertible to `T`.
-  template <
-      typename U = T,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              internal_statusor::IsDirectInitializationValid<T, U&&>,
-              std::is_constructible<T, U&&>, std::is_convertible<U&&, T>,
-              y_absl::disjunction<
-                  std::is_same<y_absl::remove_cvref_t<U>, T>,
-                  y_absl::conjunction<
-                      y_absl::negation<std::is_convertible<U&&, y_absl::Status>>,
-                      y_absl::negation<
-                          internal_statusor::HasConversionOperatorToStatusOr<
-                              T, U&&>>>>>::value,
-          int> = 0>
+  template <typename U = T,
+            y_absl::enable_if_t<internal_statusor::IsConstructionValid<
+                                  false, T, U, false>::value,
+                              int> = 0>
   StatusOr(U&& u)  // NOLINT
       : StatusOr(y_absl::in_place, std::forward<U>(u)) {}
+  template <typename U = T,
+            y_absl::enable_if_t<internal_statusor::IsConstructionValid<
+                                  false, T, U, true>::value,
+                              int> = 0>
+  StatusOr(U&& u Y_ABSL_ATTRIBUTE_LIFETIME_BOUND)  // NOLINT
+      : StatusOr(y_absl::in_place, std::forward<U>(u)) {}
 
-  template <
-      typename U = T,
-      y_absl::enable_if_t<
-          y_absl::conjunction<
-              internal_statusor::IsDirectInitializationValid<T, U&&>,
-              y_absl::disjunction<
-                  std::is_same<y_absl::remove_cvref_t<U>, T>,
-                  y_absl::conjunction<
-                      y_absl::negation<std::is_constructible<y_absl::Status, U&&>>,
-                      y_absl::negation<
-                          internal_statusor::HasConversionOperatorToStatusOr<
-                              T, U&&>>>>,
-              std::is_constructible<T, U&&>,
-              y_absl::negation<std::is_convertible<U&&, T>>>::value,
-          int> = 0>
+  template <typename U = T,
+            y_absl::enable_if_t<internal_statusor::IsConstructionValid<
+                                  true, T, U, false>::value,
+                              int> = 0>
   explicit StatusOr(U&& u)  // NOLINT
       : StatusOr(y_absl::in_place, std::forward<U>(u)) {}
+  template <typename U = T,
+            y_absl::enable_if_t<
+                internal_statusor::IsConstructionValid<true, T, U, true>::value,
+                int> = 0>
+  explicit StatusOr(U&& u Y_ABSL_ATTRIBUTE_LIFETIME_BOUND)  // NOLINT
+      : StatusOr(y_absl::in_place, std::forward<U>(u)) {}
 
   // StatusOr<T>::ok()
   //
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/ascii.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/ascii.cc
index 0d8a1d838e..81cfceabcc 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/ascii.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/ascii.cc
@@ -15,13 +15,14 @@
 #include "y_absl/strings/ascii.h"
 
 #include <climits>
-#include <cstdint>
+#include <cstddef>
 #include <cstring>
 #include <util/generic/string.h>
-#include <type_traits>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/nullability.h"
+#include "y_absl/base/optimization.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
@@ -162,19 +163,6 @@ Y_ABSL_DLL const char kToUpper[256] = {
 };
 // clang-format on
 
-template <class T>
-static constexpr T BroadcastByte(unsigned char value) {
-  static_assert(std::is_integral<T>::value && sizeof(T) <= sizeof(uint64_t) &&
-                    std::is_unsigned<T>::value,
-                "only unsigned integers up to 64-bit allowed");
-  T result = value;
-  constexpr size_t result_bit_width = sizeof(result) * CHAR_BIT;
-  result |= result << ((CHAR_BIT << 0) & (result_bit_width - 1));
-  result |= result << ((CHAR_BIT << 1) & (result_bit_width - 1));
-  result |= result << ((CHAR_BIT << 2) & (result_bit_width - 1));
-  return result;
-}
-
 // Returns whether `c` is in the a-z/A-Z range (w.r.t. `ToUpper`).
 // Implemented by:
 //  1. Pushing the a-z/A-Z range to [SCHAR_MIN, SCHAR_MIN + 26).
@@ -189,47 +177,10 @@ constexpr bool AsciiInAZRange(unsigned char c) {
   return static_cast<signed char>(u) < threshold;
 }
 
+// Force-inline so the compiler won't merge the short and long implementations.
 template <bool ToUpper>
-static constexpr char* PartialAsciiStrCaseFold(y_absl::Nonnull<char*> p,
-                                               y_absl::Nonnull<char*> end) {
-  using vec_t = size_t;
-  const size_t n = static_cast<size_t>(end - p);
-
-  // SWAR algorithm: http://0x80.pl/notesen/2016-01-06-swar-swap-case.html
-  constexpr char ch_a = ToUpper ? 'a' : 'A', ch_z = ToUpper ? 'z' : 'Z';
-  char* const swar_end = p + (n / sizeof(vec_t)) * sizeof(vec_t);
-  while (p < swar_end) {
-    vec_t v = vec_t();
-
-    // memcpy the vector, but constexpr
-    for (size_t i = 0; i < sizeof(vec_t); ++i) {
-      v |= static_cast<vec_t>(static_cast<unsigned char>(p[i]))
-           << (i * CHAR_BIT);
-    }
-
-    constexpr unsigned int msb = 1u << (CHAR_BIT - 1);
-    const vec_t v_msb = v & BroadcastByte<vec_t>(msb);
-    const vec_t v_nonascii_mask = (v_msb << 1) - (v_msb >> (CHAR_BIT - 1));
-    const vec_t v_nonascii = v & v_nonascii_mask;
-    const vec_t v_ascii = v & ~v_nonascii_mask;
-    const vec_t a = v_ascii + BroadcastByte<vec_t>(msb - ch_a - 0),
-                z = v_ascii + BroadcastByte<vec_t>(msb - ch_z - 1);
-    v = v_nonascii | (v_ascii ^ ((a ^ z) & BroadcastByte<vec_t>(msb)) >> 2);
-
-    // memcpy the vector, but constexpr
-    for (size_t i = 0; i < sizeof(vec_t); ++i) {
-      p[i] = static_cast<char>(v >> (i * CHAR_BIT));
-    }
-
-    p += sizeof(v);
-  }
-
-  return p;
-}
-
-template <bool ToUpper>
-static constexpr void AsciiStrCaseFold(y_absl::Nonnull<char*> p,
-                                       y_absl::Nonnull<char*> end) {
+Y_ABSL_ATTRIBUTE_ALWAYS_INLINE inline constexpr void AsciiStrCaseFoldImpl(
+    y_absl::Nonnull<char*> p, size_t size) {
   // The upper- and lowercase versions of ASCII characters differ by only 1 bit.
   // When we need to flip the case, we can xor with this bit to achieve the
   // desired result. Note that the choice of 'a' and 'A' here is arbitrary. We
@@ -237,20 +188,32 @@ static constexpr void AsciiStrCaseFold(y_absl::Nonnull<char*> p,
   // have the same single bit difference.
   constexpr unsigned char kAsciiCaseBitFlip = 'a' ^ 'A';
 
-  using vec_t = size_t;
-  // TODO(b/316380338): When FDO becomes able to vectorize these,
-  // revert this manual optimization and just leave the naive loop.
-  if (static_cast<size_t>(end - p) >= sizeof(vec_t)) {
-    p = ascii_internal::PartialAsciiStrCaseFold<ToUpper>(p, end);
-  }
-  while (p < end) {
-    unsigned char v = static_cast<unsigned char>(*p);
+  for (size_t i = 0; i < size; ++i) {
+    unsigned char v = static_cast<unsigned char>(p[i]);
     v ^= AsciiInAZRange<ToUpper>(v) ? kAsciiCaseBitFlip : 0;
-    *p = static_cast<char>(v);
-    ++p;
+    p[i] = static_cast<char>(v);
   }
 }
 
+// The string size threshold for starting using the long string version.
+constexpr size_t kCaseFoldThreshold = 16;
+
+// No-inline so the compiler won't merge the short and long implementations.
+template <bool ToUpper>
+Y_ABSL_ATTRIBUTE_NOINLINE constexpr void AsciiStrCaseFoldLong(
+    y_absl::Nonnull<char*> p, size_t size) {
+  Y_ABSL_ASSUME(size >= kCaseFoldThreshold);
+  AsciiStrCaseFoldImpl<ToUpper>(p, size);
+}
+
+// Splitting to short and long strings to allow vectorization decisions
+// to be made separately in the long and short cases.
+template <bool ToUpper>
+constexpr void AsciiStrCaseFold(y_absl::Nonnull<char*> p, size_t size) {
+  size < kCaseFoldThreshold ? AsciiStrCaseFoldImpl<ToUpper>(p, size)
+                            : AsciiStrCaseFoldLong<ToUpper>(p, size);
+}
+
 static constexpr size_t ValidateAsciiCasefold() {
   constexpr size_t num_chars = 1 + CHAR_MAX - CHAR_MIN;
   size_t incorrect_index = 0;
@@ -259,8 +222,8 @@ static constexpr size_t ValidateAsciiCasefold() {
   for (unsigned int i = 0; i < num_chars; ++i) {
     uppered[i] = lowered[i] = static_cast<char>(i);
   }
-  AsciiStrCaseFold<false>(&lowered[0], &lowered[num_chars]);
-  AsciiStrCaseFold<true>(&uppered[0], &uppered[num_chars]);
+  AsciiStrCaseFold<false>(&lowered[0], num_chars);
+  AsciiStrCaseFold<true>(&uppered[0], num_chars);
   for (size_t i = 0; i < num_chars; ++i) {
     const char ch = static_cast<char>(i),
                ch_upper = ('a' <= ch && ch <= 'z' ? 'A' + (ch - 'a') : ch),
@@ -278,13 +241,11 @@ static_assert(ValidateAsciiCasefold() == 0, "error in case conversion");
 }  // namespace ascii_internal
 
 void AsciiStrToLower(y_absl::Nonnull<TString*> s) {
-  char* p = &(*s)[0];  // Guaranteed to be valid for empty strings
-  return ascii_internal::AsciiStrCaseFold<false>(p, p + s->size());
+  return ascii_internal::AsciiStrCaseFold<false>(&(*s)[0], s->size());
 }
 
 void AsciiStrToUpper(y_absl::Nonnull<TString*> s) {
-  char* p = &(*s)[0];  // Guaranteed to be valid for empty strings
-  return ascii_internal::AsciiStrCaseFold<true>(p, p + s->size());
+  return ascii_internal::AsciiStrCaseFold<true>(&(*s)[0], s->size());
 }
 
 void RemoveExtraAsciiWhitespace(y_absl::Nonnull<TString*> str) {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.cc
index a1e7c30bca..93d332578a 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.cc
@@ -75,7 +75,7 @@ using ::y_absl::cord_internal::kMinFlatLength;
 using ::y_absl::cord_internal::kInlinedVectorSize;
 using ::y_absl::cord_internal::kMaxBytesToCopy;
 
-static void DumpNode(y_absl::Nonnull<CordRep*> rep, bool include_data,
+static void DumpNode(y_absl::Nonnull<CordRep*> nonnull_rep, bool include_data,
                      y_absl::Nonnull<std::ostream*> os, int indent = 0);
 static bool VerifyNode(y_absl::Nonnull<CordRep*> root,
                        y_absl::Nonnull<CordRep*> start_node);
@@ -425,8 +425,8 @@ Cord& Cord::operator=(y_absl::string_view src) {
 // we keep it here to make diffs easier.
 void Cord::InlineRep::AppendArray(y_absl::string_view src,
                                   MethodIdentifier method) {
-  MaybeRemoveEmptyCrcNode();
   if (src.empty()) return;  // memcpy(_, nullptr, 0) is undefined.
+  MaybeRemoveEmptyCrcNode();
 
   size_t appended = 0;
   CordRep* rep = tree();
@@ -1062,6 +1062,15 @@ void CopyCordToString(const Cord& src, y_absl::Nonnull<TString*> dst) {
   }
 }
 
+void AppendCordToString(const Cord& src, y_absl::Nonnull<TString*> dst) {
+  const size_t cur_dst_size = dst->size();
+  const size_t new_dst_size = cur_dst_size + src.size();
+  y_absl::strings_internal::STLStringResizeUninitializedAmortized(dst,
+                                                                new_dst_size);
+  char* append_ptr = &(*dst)[cur_dst_size];
+  src.CopyToArrayImpl(append_ptr);
+}
+
 void Cord::CopyToArraySlowPath(y_absl::Nonnull<char*> dst) const {
   assert(contents_.is_tree());
   y_absl::string_view fragment;
@@ -1448,14 +1457,13 @@ y_absl::string_view Cord::FlattenSlowPath() {
   }
 }
 
-static void DumpNode(y_absl::Nonnull<CordRep*> rep, bool include_data,
+static void DumpNode(y_absl::Nonnull<CordRep*> nonnull_rep, bool include_data,
                      y_absl::Nonnull<std::ostream*> os, int indent) {
+  CordRep* rep = nonnull_rep;
   const int kIndentStep = 1;
-  y_absl::InlinedVector<CordRep*, kInlinedVectorSize> stack;
-  y_absl::InlinedVector<int, kInlinedVectorSize> indents;
   for (;;) {
-    *os << std::setw(3) << rep->refcount.Get();
-    *os << " " << std::setw(7) << rep->length;
+    *os << std::setw(3) << (rep == nullptr ? 0 : rep->refcount.Get());
+    *os << " " << std::setw(7) << (rep == nullptr ? 0 : rep->length);
     *os << " [";
     if (include_data) *os << static_cast<void*>(rep);
     *os << "]";
@@ -1477,26 +1485,23 @@ static void DumpNode(y_absl::Nonnull<CordRep*> rep, bool include_data,
       if (rep->IsExternal()) {
         *os << "EXTERNAL [";
         if (include_data)
-          *os << y_absl::CEscape(TString(rep->external()->base, rep->length));
+          *os << y_absl::CEscape(
+              y_absl::string_view(rep->external()->base, rep->length));
         *os << "]\n";
       } else if (rep->IsFlat()) {
         *os << "FLAT cap=" << rep->flat()->Capacity() << " [";
         if (include_data)
-          *os << y_absl::CEscape(TString(rep->flat()->Data(), rep->length));
+          *os << y_absl::CEscape(
+              y_absl::string_view(rep->flat()->Data(), rep->length));
         *os << "]\n";
       } else {
         CordRepBtree::Dump(rep, /*label=*/"", include_data, *os);
       }
     }
     if (leaf) {
-      if (stack.empty()) break;
-      rep = stack.back();
-      stack.pop_back();
-      indent = indents.back();
-      indents.pop_back();
+      break;
     }
   }
-  Y_ABSL_INTERNAL_CHECK(indents.empty(), "");
 }
 
 static TString ReportError(y_absl::Nonnull<CordRep*> root,
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.h
index e1ece24382..eabfc9d920 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/cord.h
@@ -75,6 +75,7 @@
 #include "y_absl/base/internal/per_thread_tls.h"
 #include "y_absl/base/macros.h"
 #include "y_absl/base/nullability.h"
+#include "y_absl/base/optimization.h"
 #include "y_absl/base/port.h"
 #include "y_absl/container/inlined_vector.h"
 #include "y_absl/crc/internal/crc_cord_state.h"
@@ -95,6 +96,7 @@
 #include "y_absl/strings/internal/resize_uninitialized.h"
 #include "y_absl/strings/internal/string_constant.h"
 #include "y_absl/strings/string_view.h"
+#include "y_absl/types/compare.h"
 #include "y_absl/types/optional.h"
 
 namespace y_absl {
@@ -104,6 +106,7 @@ class CordTestPeer;
 template <typename Releaser>
 Cord MakeCordFromExternal(y_absl::string_view, Releaser&&);
 void CopyCordToString(const Cord& src, y_absl::Nonnull<TString*> dst);
+void AppendCordToString(const Cord& src, y_absl::Nonnull<TString*> dst);
 
 // Cord memory accounting modes
 enum class CordMemoryAccounting {
@@ -420,6 +423,18 @@ class Cord {
   friend void CopyCordToString(const Cord& src,
                                y_absl::Nonnull<TString*> dst);
 
+  // AppendCordToString()
+  //
+  // Appends the contents of a `src` Cord to a `*dst` string.
+  //
+  // This function optimizes the case of appending to a non-empty destination
+  // string. If `*dst` already has capacity to store the contents of the cord,
+  // this function does not invalidate pointers previously returned by
+  // `dst->data()`. If `*dst` is a new object, prefer to simply use the
+  // conversion operator to `TString`.
+  friend void AppendCordToString(const Cord& src,
+                                 y_absl::Nonnull<TString*> dst);
+
   class CharIterator;
 
   //----------------------------------------------------------------------------
@@ -757,7 +772,7 @@ class Cord {
 
   // Cord::Find()
   //
-  // Returns an iterator to the first occurrance of the substring `needle`.
+  // Returns an iterator to the first occurrence of the substring `needle`.
   //
   // If the substring `needle` does not occur, `Cord::char_end()` is returned.
   CharIterator Find(y_absl::string_view needle) const;
@@ -835,6 +850,38 @@ class Cord {
   friend bool operator==(const Cord& lhs, const Cord& rhs);
   friend bool operator==(const Cord& lhs, y_absl::string_view rhs);
 
+#ifdef __cpp_impl_three_way_comparison
+
+  // Cords support comparison with other Cords and string_views via operator<
+  // and others; here we provide a wrapper for the C++20 three-way comparison
+  // <=> operator.
+
+  static inline std::strong_ordering ConvertCompareResultToStrongOrdering(
+      int c) {
+    if (c == 0) {
+      return std::strong_ordering::equal;
+    } else if (c < 0) {
+      return std::strong_ordering::less;
+    } else {
+      return std::strong_ordering::greater;
+    }
+  }
+
+  friend inline std::strong_ordering operator<=>(const Cord& x, const Cord& y) {
+    return ConvertCompareResultToStrongOrdering(x.Compare(y));
+  }
+
+  friend inline std::strong_ordering operator<=>(const Cord& lhs,
+                                                 y_absl::string_view rhs) {
+    return ConvertCompareResultToStrongOrdering(lhs.Compare(rhs));
+  }
+
+  friend inline std::strong_ordering operator<=>(y_absl::string_view lhs,
+                                                 const Cord& rhs) {
+    return ConvertCompareResultToStrongOrdering(-rhs.Compare(lhs));
+  }
+#endif
+
   friend y_absl::Nullable<const CordzInfo*> GetCordzInfoForTesting(
       const Cord& cord);
 
@@ -1065,6 +1112,8 @@ class Cord {
       const;
 
   CharIterator FindImpl(CharIterator it, y_absl::string_view needle) const;
+
+  void CopyToArrayImpl(y_absl::Nonnull<char*> dst) const;
 };
 
 Y_ABSL_NAMESPACE_END
@@ -1103,8 +1152,8 @@ y_absl::Nonnull<CordRep*> NewExternalRep(y_absl::string_view data,
 // Overload for function reference types that dispatches using a function
 // pointer because there are no `alignof()` or `sizeof()` a function reference.
 // NOLINTNEXTLINE - suppress clang-tidy raw pointer return.
-inline y_absl::Nonnull<CordRep*> NewExternalRep(y_absl::string_view data,
-                               void (&releaser)(y_absl::string_view)) {
+inline y_absl::Nonnull<CordRep*> NewExternalRep(
+    y_absl::string_view data, void (&releaser)(y_absl::string_view)) {
   return NewExternalRep(data, &releaser);
 }
 
@@ -1120,7 +1169,7 @@ Cord MakeCordFromExternal(y_absl::string_view data, Releaser&& releaser) {
   } else {
     using ReleaserType = y_absl::decay_t<Releaser>;
     cord_internal::InvokeReleaser(
-        cord_internal::Rank0{}, ReleaserType(std::forward<Releaser>(releaser)),
+        cord_internal::Rank1{}, ReleaserType(std::forward<Releaser>(releaser)),
         data);
   }
   return cord;
@@ -1170,7 +1219,8 @@ inline void Cord::InlineRep::Swap(y_absl::Nonnull<Cord::InlineRep*> rhs) {
   if (rhs == this) {
     return;
   }
-  std::swap(data_, rhs->data_);
+  using std::swap;
+  swap(data_, rhs->data_);
 }
 
 inline y_absl::Nullable<const char*> Cord::InlineRep::data() const {
@@ -1352,7 +1402,8 @@ inline size_t Cord::EstimatedMemoryUsage(
   return result;
 }
 
-inline y_absl::optional<y_absl::string_view> Cord::TryFlat() const {
+inline y_absl::optional<y_absl::string_view> Cord::TryFlat() const
+    Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
   y_absl::cord_internal::CordRep* rep = contents_.tree();
   if (rep == nullptr) {
     return y_absl::string_view(contents_.data(), contents_.size());
@@ -1364,7 +1415,7 @@ inline y_absl::optional<y_absl::string_view> Cord::TryFlat() const {
   return y_absl::nullopt;
 }
 
-inline y_absl::string_view Cord::Flatten() {
+inline y_absl::string_view Cord::Flatten() Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
   y_absl::cord_internal::CordRep* rep = contents_.tree();
   if (rep == nullptr) {
     return y_absl::string_view(contents_.data(), contents_.size());
@@ -1387,6 +1438,7 @@ inline void Cord::Prepend(y_absl::string_view src) {
 
 inline void Cord::Append(CordBuffer buffer) {
   if (Y_ABSL_PREDICT_FALSE(buffer.length() == 0)) return;
+  contents_.MaybeRemoveEmptyCrcNode();
   y_absl::string_view short_value;
   if (CordRep* rep = buffer.ConsumeValue(short_value)) {
     contents_.AppendTree(rep, CordzUpdateTracker::kAppendCordBuffer);
@@ -1397,6 +1449,7 @@ inline void Cord::Append(CordBuffer buffer) {
 
 inline void Cord::Prepend(CordBuffer buffer) {
   if (Y_ABSL_PREDICT_FALSE(buffer.length() == 0)) return;
+  contents_.MaybeRemoveEmptyCrcNode();
   y_absl::string_view short_value;
   if (CordRep* rep = buffer.ConsumeValue(short_value)) {
     contents_.PrependTree(rep, CordzUpdateTracker::kPrependCordBuffer);
@@ -1445,6 +1498,14 @@ inline bool Cord::StartsWith(y_absl::string_view rhs) const {
   return EqualsImpl(rhs, rhs_size);
 }
 
+inline void Cord::CopyToArrayImpl(y_absl::Nonnull<char*> dst) const {
+  if (!contents_.is_tree()) {
+    if (!empty()) contents_.CopyToArray(dst);
+  } else {
+    CopyToArraySlowPath(dst);
+  }
+}
+
 inline void Cord::ChunkIterator::InitTree(
     y_absl::Nonnull<cord_internal::CordRep*> tree) {
   tree = cord_internal::SkipCrcNode(tree);
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.cc
index 78a706a1be..73eb224803 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.cc
@@ -21,10 +21,12 @@
 #include <cstring>
 #include <limits>
 #include <util/generic/string.h>
+#include <utility>
 
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/raw_logging.h"
 #include "y_absl/base/internal/unaligned_access.h"
+#include "y_absl/base/nullability.h"
 #include "y_absl/strings/ascii.h"
 #include "y_absl/strings/charset.h"
 #include "y_absl/strings/internal/escaping.h"
@@ -54,7 +56,8 @@ inline unsigned int hex_digit_to_int(char c) {
   return x & 0xf;
 }
 
-inline bool IsSurrogate(char32_t c, y_absl::string_view src, TString* error) {
+inline bool IsSurrogate(char32_t c, y_absl::string_view src,
+                        y_absl::Nullable<TString*> error) {
   if (c >= 0xD800 && c <= 0xDFFF) {
     if (error) {
       *error = y_absl::StrCat("invalid surrogate character (0xD800-DFFF): \\",
@@ -83,7 +86,9 @@ inline bool IsSurrogate(char32_t c, y_absl::string_view src, TString* error) {
 //     UnescapeCEscapeSequences().
 // ----------------------------------------------------------------------
 bool CUnescapeInternal(y_absl::string_view source, bool leave_nulls_escaped,
-                       char* dest, ptrdiff_t* dest_len, TString* error) {
+                       y_absl::Nonnull<char*> dest,
+                       y_absl::Nonnull<ptrdiff_t*> dest_len,
+                       y_absl::Nullable<TString*> error) {
   char* d = dest;
   const char* p = source.data();
   const char* end = p + source.size();
@@ -290,7 +295,8 @@ bool CUnescapeInternal(y_absl::string_view source, bool leave_nulls_escaped,
 //    may be the same.
 // ----------------------------------------------------------------------
 bool CUnescapeInternal(y_absl::string_view source, bool leave_nulls_escaped,
-                       TString* dest, TString* error) {
+                       y_absl::Nonnull<TString*> dest,
+                       y_absl::Nullable<TString*> error) {
   strings_internal::STLStringResizeUninitialized(dest, source.size());
 
   ptrdiff_t dest_size;
@@ -407,7 +413,8 @@ inline size_t CEscapedLength(y_absl::string_view src) {
   return escaped_len;
 }
 
-void CEscapeAndAppendInternal(y_absl::string_view src, TString* dest) {
+void CEscapeAndAppendInternal(y_absl::string_view src,
+                              y_absl::Nonnull<TString*> dest) {
   size_t escaped_len = CEscapedLength(src);
   if (escaped_len == src.size()) {
     dest->append(src.data(), src.size());
@@ -464,9 +471,10 @@ void CEscapeAndAppendInternal(y_absl::string_view src, TString* dest) {
 
 // Reverses the mapping in Base64EscapeInternal; see that method's
 // documentation for details of the mapping.
-bool Base64UnescapeInternal(const char* src_param, size_t szsrc, char* dest,
-                            size_t szdest, const signed char* unbase64,
-                            size_t* len) {
+bool Base64UnescapeInternal(y_absl::Nullable<const char*> src_param, size_t szsrc,
+                            y_absl::Nullable<char*> dest, size_t szdest,
+                            y_absl::Nonnull<const signed char*> unbase64,
+                            y_absl::Nonnull<size_t*> len) {
   static const char kPad64Equals = '=';
   static const char kPad64Dot = '.';
 
@@ -802,8 +810,9 @@ constexpr signed char kUnWebSafeBase64[] = {
 /* clang-format on */
 
 template <typename String>
-bool Base64UnescapeInternal(const char* src, size_t slen, String* dest,
-                            const signed char* unbase64) {
+bool Base64UnescapeInternal(y_absl::Nullable<const char*> src, size_t slen,
+                            y_absl::Nonnull<String*> dest,
+                            y_absl::Nonnull<const signed char*> unbase64) {
   // Determine the size of the output string.  Base64 encodes every 3 bytes into
   // 4 characters.  Any leftover chars are added directly for good measure.
   const size_t dest_len = 3 * (slen / 4) + (slen % 4);
@@ -847,13 +856,32 @@ constexpr char kHexValueLenient[256] = {
     0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 };
 
+constexpr signed char kHexValueStrict[256] = {
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+     0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1,  // '0'..'9'
+    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 'A'..'F'
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 'a'..'f'
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+};
 /* clang-format on */
 
 // This is a templated function so that T can be either a char*
 // or a string.  This works because we use the [] operator to access
 // individual characters at a time.
 template <typename T>
-void HexStringToBytesInternal(const char* from, T to, size_t num) {
+void HexStringToBytesInternal(y_absl::Nullable<const char*> from, T to,
+                              size_t num) {
   for (size_t i = 0; i < num; i++) {
     to[i] = static_cast<char>(kHexValueLenient[from[i * 2] & 0xFF] << 4) +
             (kHexValueLenient[from[i * 2 + 1] & 0xFF]);
@@ -863,7 +891,8 @@ void HexStringToBytesInternal(const char* from, T to, size_t num) {
 // This is a templated function so that T can be either a char* or a
 // TString.
 template <typename T>
-void BytesToHexStringInternal(const unsigned char* src, T dest, size_t num) {
+void BytesToHexStringInternal(y_absl::Nullable<const unsigned char*> src, T dest,
+                              size_t num) {
   auto dest_ptr = &dest[0];
   for (auto src_ptr = src; src_ptr != (src + num); ++src_ptr, dest_ptr += 2) {
     const char* hex_p = &numbers_internal::kHexTable[*src_ptr * 2];
@@ -878,8 +907,8 @@ void BytesToHexStringInternal(const unsigned char* src, T dest, size_t num) {
 //
 // See CUnescapeInternal() for implementation details.
 // ----------------------------------------------------------------------
-bool CUnescape(y_absl::string_view source, TString* dest,
-               TString* error) {
+bool CUnescape(y_absl::string_view source, y_absl::Nonnull<TString*> dest,
+               y_absl::Nullable<TString*> error) {
   return CUnescapeInternal(source, kUnescapeNulls, dest, error);
 }
 
@@ -901,21 +930,23 @@ TString Utf8SafeCHexEscape(y_absl::string_view src) {
   return CEscapeInternal(src, true, true);
 }
 
-bool Base64Unescape(y_absl::string_view src, TString* dest) {
+bool Base64Unescape(y_absl::string_view src, y_absl::Nonnull<TString*> dest) {
   return Base64UnescapeInternal(src.data(), src.size(), dest, kUnBase64);
 }
 
-bool WebSafeBase64Unescape(y_absl::string_view src, TString* dest) {
+bool WebSafeBase64Unescape(y_absl::string_view src,
+                           y_absl::Nonnull<TString*> dest) {
   return Base64UnescapeInternal(src.data(), src.size(), dest, kUnWebSafeBase64);
 }
 
-void Base64Escape(y_absl::string_view src, TString* dest) {
+void Base64Escape(y_absl::string_view src, y_absl::Nonnull<TString*> dest) {
   strings_internal::Base64EscapeInternal(
       reinterpret_cast<const unsigned char*>(src.data()), src.size(), dest,
       true, strings_internal::kBase64Chars);
 }
 
-void WebSafeBase64Escape(y_absl::string_view src, TString* dest) {
+void WebSafeBase64Escape(y_absl::string_view src,
+                         y_absl::Nonnull<TString*> dest) {
   strings_internal::Base64EscapeInternal(
       reinterpret_cast<const unsigned char*>(src.data()), src.size(), dest,
       false, strings_internal::kWebSafeBase64Chars);
@@ -937,6 +968,32 @@ TString WebSafeBase64Escape(y_absl::string_view src) {
   return dest;
 }
 
+bool HexStringToBytes(y_absl::string_view hex,
+                      y_absl::Nonnull<TString*> bytes) {
+  TString output;
+
+  size_t num_bytes = hex.size() / 2;
+  if (hex.size() != num_bytes * 2) {
+    return false;
+  }
+
+  y_absl::strings_internal::STLStringResizeUninitialized(&output, num_bytes);
+  auto hex_p = hex.cbegin();
+  for (TString::iterator bin_p = output.begin(); bin_p != output.end();
+       ++bin_p) {
+    int h1 = y_absl::kHexValueStrict[static_cast<size_t>(*hex_p++)];
+    int h2 = y_absl::kHexValueStrict[static_cast<size_t>(*hex_p++)];
+    if (h1 == -1 || h2 == -1) {
+      output.resize(static_cast<size_t>(bin_p - output.begin()));
+      return false;
+    }
+    *bin_p = static_cast<char>((h1 << 4) + h2);
+  }
+
+  *bytes = std::move(output);
+  return true;
+}
+
 TString HexStringToBytes(y_absl::string_view from) {
   TString result;
   const auto num = from.size() / 2;
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.h
index 3b5e0537b6..8cadf95e7a 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/escaping.h
@@ -27,7 +27,9 @@
 #include <util/generic/string.h>
 #include <vector>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/macros.h"
+#include "y_absl/base/nullability.h"
 #include "y_absl/strings/ascii.h"
 #include "y_absl/strings/str_join.h"
 #include "y_absl/strings/string_view.h"
@@ -65,14 +67,16 @@ Y_ABSL_NAMESPACE_BEGIN
 //
 //   TString s = "foo\\rbar\\nbaz\\t";
 //   TString unescaped_s;
-//   if (!y_absl::CUnescape(s, &unescaped_s) {
+//   if (!y_absl::CUnescape(s, &unescaped_s)) {
 //     ...
 //   }
 //   EXPECT_EQ(unescaped_s, "foo\rbar\nbaz\t");
-bool CUnescape(y_absl::string_view source, TString* dest, TString* error);
+bool CUnescape(y_absl::string_view source, y_absl::Nonnull<TString*> dest,
+               y_absl::Nullable<TString*> error);
 
 // Overload of `CUnescape()` with no error reporting.
-inline bool CUnescape(y_absl::string_view source, TString* dest) {
+inline bool CUnescape(y_absl::string_view source,
+                      y_absl::Nonnull<TString*> dest) {
   return CUnescape(source, dest, nullptr);
 }
 
@@ -122,7 +126,7 @@ TString Utf8SafeCHexEscape(y_absl::string_view src);
 // Encodes a `src` string into a base64-encoded 'dest' string with padding
 // characters. This function conforms with RFC 4648 section 4 (base64) and RFC
 // 2045.
-void Base64Escape(y_absl::string_view src, TString* dest);
+void Base64Escape(y_absl::string_view src, y_absl::Nonnull<TString*> dest);
 TString Base64Escape(y_absl::string_view src);
 
 // WebSafeBase64Escape()
@@ -130,7 +134,8 @@ TString Base64Escape(y_absl::string_view src);
 // Encodes a `src` string into a base64 string, like Base64Escape() does, but
 // outputs '-' instead of '+' and '_' instead of '/', and does not pad 'dest'.
 // This function conforms with RFC 4648 section 5 (base64url).
-void WebSafeBase64Escape(y_absl::string_view src, TString* dest);
+void WebSafeBase64Escape(y_absl::string_view src,
+                         y_absl::Nonnull<TString*> dest);
 TString WebSafeBase64Escape(y_absl::string_view src);
 
 // Base64Unescape()
@@ -140,7 +145,7 @@ TString WebSafeBase64Escape(y_absl::string_view src);
 // `src` contains invalid characters, `dest` is cleared and returns `false`.
 // If padding is included (note that `Base64Escape()` does produce it), it must
 // be correct. In the padding, '=' and '.' are treated identically.
-bool Base64Unescape(y_absl::string_view src, TString* dest);
+bool Base64Unescape(y_absl::string_view src, y_absl::Nonnull<TString*> dest);
 
 // WebSafeBase64Unescape()
 //
@@ -149,12 +154,24 @@ bool Base64Unescape(y_absl::string_view src, TString* dest);
 // invalid characters, `dest` is cleared and returns `false`. If padding is
 // included (note that `WebSafeBase64Escape()` does not produce it), it must be
 // correct. In the padding, '=' and '.' are treated identically.
-bool WebSafeBase64Unescape(y_absl::string_view src, TString* dest);
+bool WebSafeBase64Unescape(y_absl::string_view src,
+                           y_absl::Nonnull<TString*> dest);
+
+// HexStringToBytes()
+//
+// Converts the hexadecimal encoded data in `hex` into raw bytes in the `bytes`
+// output string.  If `hex` does not consist of valid hexadecimal data, this
+// function returns false and leaves `bytes` in an unspecified state. Returns
+// true on success.
+Y_ABSL_MUST_USE_RESULT bool HexStringToBytes(y_absl::string_view hex,
+                                           y_absl::Nonnull<TString*> bytes);
 
 // HexStringToBytes()
 //
 // Converts an ASCII hex string into bytes, returning binary data of length
-// `from.size()/2`.
+// `from.size()/2`. The input must be valid hexadecimal data, otherwise the
+// return value is unspecified.
+Y_ABSL_DEPRECATED("Use the HexStringToBytes() that returns a bool")
 TString HexStringToBytes(y_absl::string_view from);
 
 // BytesToHexString()
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/has_absl_stringify.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/has_absl_stringify.h
index 1ee2e96f99..6304317c1a 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/has_absl_stringify.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/has_absl_stringify.h
@@ -18,6 +18,7 @@
 #include <type_traits>
 #include <utility>
 
+#include "y_absl/base/config.h"
 #include "y_absl/strings/string_view.h"
 
 namespace y_absl {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/charconv_bigint.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/charconv_bigint.h
index fe9a61f943..6264dc9e80 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/charconv_bigint.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/charconv_bigint.h
@@ -109,7 +109,17 @@ class BigUnsigned {
       size_ = (std::min)(size_ + word_shift, max_words);
       count %= 32;
       if (count == 0) {
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=warray-bounds
+// shows a lot of bogus -Warray-bounds warnings under GCC.
+// This is not the only one in Abseil.
+#if Y_ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(14, 0)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+#endif
         std::copy_backward(words_, words_ + size_ - word_shift, words_ + size_);
+#if Y_ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(14, 0)
+#pragma GCC diagnostic pop
+#endif
       } else {
         for (int i = (std::min)(size_, max_words - 1); i > word_shift; --i) {
           words_[i] = (words_[i - word_shift] << count) |
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_internal.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_internal.h
index 7a03ba3337..22d6deb67a 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_internal.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_internal.h
@@ -85,7 +85,7 @@ enum Constants {
 };
 
 // Emits a fatal error "Unexpected node type: xyz" and aborts the program.
-Y_ABSL_ATTRIBUTE_NORETURN void LogFatalNodeType(CordRep* rep);
+[[noreturn]] void LogFatalNodeType(CordRep* rep);
 
 // Fast implementation of memmove for up to 15 bytes. This implementation is
 // safe for overlapping regions. If nullify_tail is true, the destination is
@@ -259,7 +259,7 @@ struct CordRep {
   // on the specific layout of these fields. Notably: the non-trivial field
   // `refcount` being preceded by `length`, and being tailed by POD data
   // members only.
-  // # LINT.IfChange
+  // LINT.IfChange
   size_t length;
   RefcountAndFlags refcount;
   // If tag < FLAT, it represents CordRepKind and indicates the type of node.
@@ -275,7 +275,7 @@ struct CordRep {
   // allocate room for these in the derived class, as not all compilers reuse
   // padding space from the base class (clang and gcc do, MSVC does not, etc)
   uint8_t storage[3];
-  // # LINT.ThenChange(cord_rep_btree.h:copy_raw)
+  // LINT.ThenChange(cord_rep_btree.h:copy_raw)
 
   // Returns true if this instance's tag matches the requested type.
   constexpr bool IsSubstring() const { return tag == SUBSTRING; }
@@ -352,18 +352,19 @@ struct CordRepExternal : public CordRep {
   static void Delete(CordRep* rep);
 };
 
-struct Rank1 {};
-struct Rank0 : Rank1 {};
+// Use go/ranked-overloads for dispatching.
+struct Rank0 {};
+struct Rank1 : Rank0 {};
 
 template <typename Releaser, typename = ::y_absl::base_internal::invoke_result_t<
                                  Releaser, y_absl::string_view>>
-void InvokeReleaser(Rank0, Releaser&& releaser, y_absl::string_view data) {
+void InvokeReleaser(Rank1, Releaser&& releaser, y_absl::string_view data) {
   ::y_absl::base_internal::invoke(std::forward<Releaser>(releaser), data);
 }
 
 template <typename Releaser,
           typename = ::y_absl::base_internal::invoke_result_t<Releaser>>
-void InvokeReleaser(Rank1, Releaser&& releaser, y_absl::string_view) {
+void InvokeReleaser(Rank0, Releaser&& releaser, y_absl::string_view) {
   ::y_absl::base_internal::invoke(std::forward<Releaser>(releaser));
 }
 
@@ -381,7 +382,7 @@ struct CordRepExternalImpl
   }
 
   ~CordRepExternalImpl() {
-    InvokeReleaser(Rank0{}, std::move(this->template get<0>()),
+    InvokeReleaser(Rank1{}, std::move(this->template get<0>()),
                    y_absl::string_view(base, length));
   }
 
@@ -398,7 +399,6 @@ inline CordRepSubstring* CordRepSubstring::Create(CordRep* child, size_t pos,
   assert(pos < child->length);
   assert(n <= child->length - pos);
 
-  // TODO(b/217376272): Harden internal logic.
   // Move to strategical places inside the Cord logic and make this an assert.
   if (Y_ABSL_PREDICT_FALSE(!(child->IsExternal() || child->IsFlat()))) {
     LogFatalNodeType(child);
@@ -520,6 +520,7 @@ class InlineData {
 
   constexpr InlineData(const InlineData& rhs) noexcept;
   InlineData& operator=(const InlineData& rhs) noexcept;
+  friend void swap(InlineData& lhs, InlineData& rhs) noexcept;
 
   friend bool operator==(const InlineData& lhs, const InlineData& rhs) {
 #ifdef Y_ABSL_INTERNAL_CORD_HAVE_SANITIZER
@@ -770,6 +771,12 @@ class InlineData {
       char data[kMaxInline + 1];
       AsTree as_tree;
     };
+
+    // TODO(b/145829486): see swap(InlineData, InlineData) for more info.
+    inline void SwapValue(Rep rhs, Rep& refrhs) {
+      memcpy(&refrhs, this, sizeof(*this));
+      memcpy(this, &rhs, sizeof(*this));
+    }
   };
 
   // Private implementation of `Compare()`
@@ -884,6 +891,19 @@ inline void CordRep::Unref(CordRep* rep) {
   }
 }
 
+inline void swap(InlineData& lhs, InlineData& rhs) noexcept {
+  lhs.unpoison();
+  rhs.unpoison();
+  // TODO(b/145829486): `std::swap(lhs.rep_, rhs.rep_)` results in bad codegen
+  // on clang, spilling the temporary swap value on the stack. Since `Rep` is
+  // trivial, we can make clang DTRT by calling a hand-rolled `SwapValue` where
+  // we pass `rhs` both by value (register allocated) and by reference. The IR
+  // then folds and inlines correctly into an optimized swap without spill.
+  lhs.rep_.SwapValue(rhs.rep_, rhs.rep_);
+  rhs.poison();
+  lhs.poison();
+}
+
 }  // namespace cord_internal
 
 Y_ABSL_NAMESPACE_END
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_rep_btree.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_rep_btree.h
index 0d5b4ad427..d527b03df7 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_rep_btree.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cord_rep_btree.h
@@ -684,14 +684,14 @@ inline CordRepBtree* CordRepBtree::CopyRaw(size_t new_length) const {
   // except `refcount` is trivially copyable, and the compiler does not
   // efficiently coalesce member-wise copy of these members.
   // See https://gcc.godbolt.org/z/qY8zsca6z
-  // # LINT.IfChange(copy_raw)
+  // LINT.IfChange(copy_raw)
   tree->length = new_length;
   uint8_t* dst = &tree->tag;
   const uint8_t* src = &tag;
   const ptrdiff_t offset = src - reinterpret_cast<const uint8_t*>(this);
   memcpy(dst, src, sizeof(CordRepBtree) - static_cast<size_t>(offset));
   return tree;
-  // # LINT.ThenChange()
+  // LINT.ThenChange()
 }
 
 inline CordRepBtree* CordRepBtree::Copy() const {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.cc
index e6038c9b30..bfa72e9609 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.cc
@@ -40,13 +40,15 @@ std::atomic<int> g_cordz_mean_interval(50000);
 // Special negative 'not initialized' per thread value for cordz_next_sample.
 static constexpr int64_t kInitCordzNextSample = -1;
 
-Y_ABSL_CONST_INIT thread_local int64_t cordz_next_sample = kInitCordzNextSample;
+Y_ABSL_CONST_INIT thread_local SamplingState cordz_next_sample = {
+    kInitCordzNextSample, 1};
 
 // kIntervalIfDisabled is the number of profile-eligible events need to occur
 // before the code will confirm that cordz is still disabled.
 constexpr int64_t kIntervalIfDisabled = 1 << 16;
 
-Y_ABSL_ATTRIBUTE_NOINLINE bool cordz_should_profile_slow() {
+Y_ABSL_ATTRIBUTE_NOINLINE int64_t
+cordz_should_profile_slow(SamplingState& state) {
 
   thread_local y_absl::profiling_internal::ExponentialBiased
       exponential_biased_generator;
@@ -55,30 +57,34 @@ Y_ABSL_ATTRIBUTE_NOINLINE bool cordz_should_profile_slow() {
   // Check if we disabled profiling. If so, set the next sample to a "large"
   // number to minimize the overhead of the should_profile codepath.
   if (mean_interval <= 0) {
-    cordz_next_sample = kIntervalIfDisabled;
-    return false;
+    state = {kIntervalIfDisabled, kIntervalIfDisabled};
+    return 0;
   }
 
   // Check if we're always sampling.
   if (mean_interval == 1) {
-    cordz_next_sample = 1;
-    return true;
+    state = {1, 1};
+    return 1;
   }
 
-  if (cordz_next_sample <= 0) {
+  if (cordz_next_sample.next_sample <= 0) {
     // If first check on current thread, check cordz_should_profile()
     // again using the created (initial) stride in cordz_next_sample.
-    const bool initialized = cordz_next_sample != kInitCordzNextSample;
-    cordz_next_sample = exponential_biased_generator.GetStride(mean_interval);
-    return initialized || cordz_should_profile();
+    const bool initialized =
+        cordz_next_sample.next_sample != kInitCordzNextSample;
+    auto old_stride = state.sample_stride;
+    auto stride = exponential_biased_generator.GetStride(mean_interval);
+    state = {stride, stride};
+    bool should_sample = initialized || cordz_should_profile() > 0;
+    return should_sample ? old_stride : 0;
   }
 
-  --cordz_next_sample;
-  return false;
+  --state.next_sample;
+  return 0;
 }
 
 void cordz_set_next_sample_for_testing(int64_t next_sample) {
-  cordz_next_sample = next_sample;
+  cordz_next_sample = {next_sample, next_sample};
 }
 
 #endif  // Y_ABSL_INTERNAL_CORDZ_ENABLED
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.h
index 0404447777..cb45562da6 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_functions.h
@@ -41,23 +41,33 @@ void set_cordz_mean_interval(int32_t mean_interval);
 
 #ifdef Y_ABSL_INTERNAL_CORDZ_ENABLED
 
+struct SamplingState {
+  int64_t next_sample;
+  int64_t sample_stride;
+};
+
 // cordz_next_sample is the number of events until the next sample event. If
 // the value is 1 or less, the code will check on the next event if cordz is
 // enabled, and if so, will sample the Cord. cordz is only enabled when we can
 // use thread locals.
-Y_ABSL_CONST_INIT extern thread_local int64_t cordz_next_sample;
-
-// Determines if the next sample should be profiled. If it is, the value pointed
-// at by next_sample will be set with the interval until the next sample.
-bool cordz_should_profile_slow();
-
-// Returns true if the next cord should be sampled.
-inline bool cordz_should_profile() {
-  if (Y_ABSL_PREDICT_TRUE(cordz_next_sample > 1)) {
-    cordz_next_sample--;
-    return false;
+Y_ABSL_CONST_INIT extern thread_local SamplingState cordz_next_sample;
+
+// Determines if the next sample should be profiled.
+// Returns:
+//   0: Do not sample
+//  >0: Sample with the stride of the last sampling period
+int64_t cordz_should_profile_slow(SamplingState& state);
+
+// Determines if the next sample should be profiled.
+// Returns:
+//   0: Do not sample
+//  >0: Sample with the stride of the last sampling period
+inline int64_t cordz_should_profile() {
+  if (Y_ABSL_PREDICT_TRUE(cordz_next_sample.next_sample > 1)) {
+    cordz_next_sample.next_sample--;
+    return 0;
   }
-  return cordz_should_profile_slow();
+  return cordz_should_profile_slow(cordz_next_sample);
 }
 
 // Sets the interval until the next sample (for testing only)
@@ -65,7 +75,7 @@ void cordz_set_next_sample_for_testing(int64_t next_sample);
 
 #else  // Y_ABSL_INTERNAL_CORDZ_ENABLED
 
-inline bool cordz_should_profile() { return false; }
+inline int64_t cordz_should_profile() { return 0; }
 inline void cordz_set_next_sample_for_testing(int64_t) {}
 
 #endif  // Y_ABSL_INTERNAL_CORDZ_ENABLED
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_handle.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_handle.cc
index 24baed9183..28334d9556 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_handle.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_handle.cc
@@ -16,6 +16,7 @@
 #include <atomic>
 
 #include "y_absl/base/internal/raw_logging.h"  // For Y_ABSL_RAW_CHECK
+#include "y_absl/base/no_destructor.h"
 #include "y_absl/synchronization/mutex.h"
 
 namespace y_absl {
@@ -43,33 +44,32 @@ struct Queue {
   }
 };
 
-static Queue* GlobalQueue() {
-  static Queue* global_queue = new Queue;
-  return global_queue;
+static Queue& GlobalQueue() {
+  static y_absl::NoDestructor<Queue> global_queue;
+  return *global_queue;
 }
 
 }  // namespace
 
 CordzHandle::CordzHandle(bool is_snapshot) : is_snapshot_(is_snapshot) {
-  Queue* global_queue = GlobalQueue();
+  Queue& global_queue = GlobalQueue();
   if (is_snapshot) {
-    MutexLock lock(&global_queue->mutex);
-    CordzHandle* dq_tail =
-        global_queue->dq_tail.load(std::memory_order_acquire);
+    MutexLock lock(&global_queue.mutex);
+    CordzHandle* dq_tail = global_queue.dq_tail.load(std::memory_order_acquire);
     if (dq_tail != nullptr) {
       dq_prev_ = dq_tail;
       dq_tail->dq_next_ = this;
     }
-    global_queue->dq_tail.store(this, std::memory_order_release);
+    global_queue.dq_tail.store(this, std::memory_order_release);
   }
 }
 
 CordzHandle::~CordzHandle() {
-  Queue* global_queue = GlobalQueue();
+  Queue& global_queue = GlobalQueue();
   if (is_snapshot_) {
     std::vector<CordzHandle*> to_delete;
     {
-      MutexLock lock(&global_queue->mutex);
+      MutexLock lock(&global_queue.mutex);
       CordzHandle* next = dq_next_;
       if (dq_prev_ == nullptr) {
         // We were head of the queue, delete every CordzHandle until we reach
@@ -85,7 +85,7 @@ CordzHandle::~CordzHandle() {
       if (next) {
         next->dq_prev_ = dq_prev_;
       } else {
-        global_queue->dq_tail.store(dq_prev_, std::memory_order_release);
+        global_queue.dq_tail.store(dq_prev_, std::memory_order_release);
       }
     }
     for (CordzHandle* handle : to_delete) {
@@ -95,20 +95,20 @@ CordzHandle::~CordzHandle() {
 }
 
 bool CordzHandle::SafeToDelete() const {
-  return is_snapshot_ || GlobalQueue()->IsEmpty();
+  return is_snapshot_ || GlobalQueue().IsEmpty();
 }
 
 void CordzHandle::Delete(CordzHandle* handle) {
   assert(handle);
   if (handle) {
-    Queue* const queue = GlobalQueue();
+    Queue& queue = GlobalQueue();
     if (!handle->SafeToDelete()) {
-      MutexLock lock(&queue->mutex);
-      CordzHandle* dq_tail = queue->dq_tail.load(std::memory_order_acquire);
+      MutexLock lock(&queue.mutex);
+      CordzHandle* dq_tail = queue.dq_tail.load(std::memory_order_acquire);
       if (dq_tail != nullptr) {
         handle->dq_prev_ = dq_tail;
         dq_tail->dq_next_ = handle;
-        queue->dq_tail.store(handle, std::memory_order_release);
+        queue.dq_tail.store(handle, std::memory_order_release);
         return;
       }
     }
@@ -118,9 +118,9 @@ void CordzHandle::Delete(CordzHandle* handle) {
 
 std::vector<const CordzHandle*> CordzHandle::DiagnosticsGetDeleteQueue() {
   std::vector<const CordzHandle*> handles;
-  Queue* global_queue = GlobalQueue();
-  MutexLock lock(&global_queue->mutex);
-  CordzHandle* dq_tail = global_queue->dq_tail.load(std::memory_order_acquire);
+  Queue& global_queue = GlobalQueue();
+  MutexLock lock(&global_queue.mutex);
+  CordzHandle* dq_tail = global_queue.dq_tail.load(std::memory_order_acquire);
   for (const CordzHandle* p = dq_tail; p; p = p->dq_prev_) {
     handles.push_back(p);
   }
@@ -133,9 +133,9 @@ bool CordzHandle::DiagnosticsHandleIsSafeToInspect(
   if (handle == nullptr) return true;
   if (handle->is_snapshot_) return false;
   bool snapshot_found = false;
-  Queue* global_queue = GlobalQueue();
-  MutexLock lock(&global_queue->mutex);
-  for (const CordzHandle* p = global_queue->dq_tail; p; p = p->dq_prev_) {
+  Queue& global_queue = GlobalQueue();
+  MutexLock lock(&global_queue.mutex);
+  for (const CordzHandle* p = global_queue.dq_tail; p; p = p->dq_prev_) {
     if (p == handle) return !snapshot_found;
     if (p == this) snapshot_found = true;
   }
@@ -150,8 +150,8 @@ CordzHandle::DiagnosticsGetSafeToInspectDeletedHandles() {
     return handles;
   }
 
-  Queue* global_queue = GlobalQueue();
-  MutexLock lock(&global_queue->mutex);
+  Queue& global_queue = GlobalQueue();
+  MutexLock lock(&global_queue.mutex);
   for (const CordzHandle* p = dq_next_; p != nullptr; p = p->dq_next_) {
     if (!p->is_snapshot()) {
       handles.push_back(p);
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.cc
index 6c3c0e6c22..320a01edd4 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.cc
@@ -14,6 +14,8 @@
 
 #include "y_absl/strings/internal/cordz_info.h"
 
+#include <cstdint>
+
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/spinlock.h"
 #include "y_absl/container/inlined_vector.h"
@@ -247,10 +249,12 @@ CordzInfo* CordzInfo::Next(const CordzSnapshot& snapshot) const {
   return next;
 }
 
-void CordzInfo::TrackCord(InlineData& cord, MethodIdentifier method) {
+void CordzInfo::TrackCord(InlineData& cord, MethodIdentifier method,
+                          int64_t sampling_stride) {
   assert(cord.is_tree());
   assert(!cord.is_profiled());
-  CordzInfo* cordz_info = new CordzInfo(cord.as_tree(), nullptr, method);
+  CordzInfo* cordz_info =
+      new CordzInfo(cord.as_tree(), nullptr, method, sampling_stride);
   cord.set_cordz_info(cordz_info);
   cordz_info->Track();
 }
@@ -266,7 +270,8 @@ void CordzInfo::TrackCord(InlineData& cord, const InlineData& src,
   if (cordz_info != nullptr) cordz_info->Untrack();
 
   // Start new cord sample
-  cordz_info = new CordzInfo(cord.as_tree(), src.cordz_info(), method);
+  cordz_info = new CordzInfo(cord.as_tree(), src.cordz_info(), method,
+                             src.cordz_info()->sampling_stride());
   cord.set_cordz_info(cordz_info);
   cordz_info->Track();
 }
@@ -298,9 +303,8 @@ size_t CordzInfo::FillParentStack(const CordzInfo* src, void** stack) {
   return src->stack_depth_;
 }
 
-CordzInfo::CordzInfo(CordRep* rep,
-                     const CordzInfo* src,
-                     MethodIdentifier method)
+CordzInfo::CordzInfo(CordRep* rep, const CordzInfo* src,
+                     MethodIdentifier method, int64_t sampling_stride)
     : rep_(rep),
       stack_depth_(
           static_cast<size_t>(y_absl::GetStackTrace(stack_,
@@ -309,7 +313,8 @@ CordzInfo::CordzInfo(CordRep* rep,
       parent_stack_depth_(FillParentStack(src, parent_stack_)),
       method_(method),
       parent_method_(GetParentMethod(src)),
-      create_time_(y_absl::Now()) {
+      create_time_(y_absl::Now()),
+      sampling_stride_(sampling_stride) {
   update_tracker_.LossyAdd(method);
   if (src) {
     // Copy parent counters.
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.h
index ca7ecab469..7bbbb9e231 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/cordz_info.h
@@ -60,7 +60,8 @@ class Y_ABSL_LOCKABLE CordzInfo : public CordzHandle {
   // and/or deleted. `method` identifies the Cord public API method initiating
   // the cord to be sampled.
   // Requires `cord` to hold a tree, and `cord.cordz_info()` to be null.
-  static void TrackCord(InlineData& cord, MethodIdentifier method);
+  static void TrackCord(InlineData& cord, MethodIdentifier method,
+                        int64_t sampling_stride);
 
   // Identical to TrackCord(), except that this function fills the
   // `parent_stack` and `parent_method` properties of the returned CordzInfo
@@ -181,6 +182,8 @@ class Y_ABSL_LOCKABLE CordzInfo : public CordzHandle {
   // or RemovePrefix.
   CordzStatistics GetCordzStatistics() const;
 
+  int64_t sampling_stride() const { return sampling_stride_; }
+
  private:
   using SpinLock = y_absl::base_internal::SpinLock;
   using SpinLockHolder = ::y_absl::base_internal::SpinLockHolder;
@@ -199,7 +202,7 @@ class Y_ABSL_LOCKABLE CordzInfo : public CordzHandle {
   static constexpr size_t kMaxStackDepth = 64;
 
   explicit CordzInfo(CordRep* rep, const CordzInfo* src,
-                     MethodIdentifier method);
+                     MethodIdentifier method, int64_t weight);
   ~CordzInfo() override;
 
   // Sets `rep_` without holding a lock.
@@ -250,12 +253,14 @@ class Y_ABSL_LOCKABLE CordzInfo : public CordzHandle {
   const MethodIdentifier parent_method_;
   CordzUpdateTracker update_tracker_;
   const y_absl::Time create_time_;
+  const int64_t sampling_stride_;
 };
 
 inline Y_ABSL_ATTRIBUTE_ALWAYS_INLINE void CordzInfo::MaybeTrackCord(
     InlineData& cord, MethodIdentifier method) {
-  if (Y_ABSL_PREDICT_FALSE(cordz_should_profile())) {
-    TrackCord(cord, method);
+  auto stride = cordz_should_profile();
+  if (Y_ABSL_PREDICT_FALSE(stride > 0)) {
+    TrackCord(cord, method, stride);
   }
 }
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/escaping.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/escaping.cc
index 94d3a21db3..cbfeed0440 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/escaping.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/escaping.cc
@@ -14,6 +14,8 @@
 
 #include "y_absl/strings/internal/escaping.h"
 
+#include <limits>
+
 #include "y_absl/base/internal/endian.h"
 #include "y_absl/base/internal/raw_logging.h"
 
@@ -31,12 +33,14 @@ Y_ABSL_CONST_INIT const char kBase64Chars[] =
 Y_ABSL_CONST_INIT const char kWebSafeBase64Chars[] =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
 
-
 size_t CalculateBase64EscapedLenInternal(size_t input_len, bool do_padding) {
   // Base64 encodes three bytes of input at a time. If the input is not
   // divisible by three, we pad as appropriate.
   //
   // Base64 encodes each three bytes of input into four bytes of output.
+  constexpr size_t kMaxSize = (std::numeric_limits<size_t>::max() - 1) / 4 * 3;
+  Y_ABSL_INTERNAL_CHECK(input_len <= kMaxSize,
+                      "CalculateBase64EscapedLenInternal() overflow");
   size_t len = (input_len / 3) * 4;
 
   // Since all base 64 input is an integral number of octets, only the following
@@ -66,7 +70,6 @@ size_t CalculateBase64EscapedLenInternal(size_t input_len, bool do_padding) {
     }
   }
 
-  assert(len >= input_len);  // make sure we didn't overflow
   return len;
 }
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_join_internal.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_join_internal.h
index d4ef8a2c86..7a1aa0585f 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_join_internal.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_join_internal.h
@@ -31,16 +31,23 @@
 #ifndef Y_ABSL_STRINGS_INTERNAL_STR_JOIN_INTERNAL_H_
 #define Y_ABSL_STRINGS_INTERNAL_STR_JOIN_INTERNAL_H_
 
+#include <cstdint>
 #include <cstring>
+#include <initializer_list>
 #include <iterator>
+#include <limits>
 #include <memory>
 #include <util/generic/string.h>
+#include <tuple>
 #include <type_traits>
 #include <utility>
 
+#include "y_absl/base/config.h"
+#include "y_absl/base/internal/raw_logging.h"
 #include "y_absl/strings/internal/ostringstream.h"
 #include "y_absl/strings/internal/resize_uninitialized.h"
 #include "y_absl/strings/str_cat.h"
+#include "y_absl/strings/string_view.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
@@ -230,14 +237,19 @@ TString JoinAlgorithm(Iterator start, Iterator end, y_absl::string_view s,
   if (start != end) {
     // Sums size
     auto&& start_value = *start;
-    size_t result_size = start_value.size();
+    // Use uint64_t to prevent size_t overflow. We assume it is not possible for
+    // in memory strings to overflow a uint64_t.
+    uint64_t result_size = start_value.size();
     for (Iterator it = start; ++it != end;) {
       result_size += s.size();
       result_size += (*it).size();
     }
 
     if (result_size > 0) {
-      STLStringResizeUninitialized(&result, result_size);
+      constexpr uint64_t kMaxSize =
+          uint64_t{(std::numeric_limits<size_t>::max)()};
+      Y_ABSL_INTERNAL_CHECK(result_size <= kMaxSize, "size_t overflow");
+      STLStringResizeUninitialized(&result, static_cast<size_t>(result_size));
 
       // Joins strings
       char* result_buf = &*result.begin();
@@ -310,6 +322,15 @@ TString JoinRange(const Range& range, y_absl::string_view separator) {
   return JoinRange(begin(range), end(range), separator);
 }
 
+template <typename Tuple, std::size_t... I>
+TString JoinTuple(const Tuple& value, y_absl::string_view separator,
+                      std::index_sequence<I...>) {
+  return JoinRange(
+      std::initializer_list<y_absl::string_view>{
+          static_cast<const AlphaNum&>(std::get<I>(value)).Piece()...},
+      separator);
+}
+
 }  // namespace strings_internal
 Y_ABSL_NAMESPACE_END
 }  // namespace y_absl
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_split_internal.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_split_internal.h
index 19afc28ee5..fff1be7aaa 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_split_internal.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/internal/str_split_internal.h
@@ -30,6 +30,7 @@
 #define Y_ABSL_STRINGS_INTERNAL_STR_SPLIT_INTERNAL_H_
 
 #include <array>
+#include <cstddef>
 #include <initializer_list>
 #include <iterator>
 #include <tuple>
@@ -402,7 +403,10 @@ class Splitter {
           ar[index].size = it->size();
           ++it;
         } while (++index != ar.size() && !it.at_end());
-        v.insert(v.end(), ar.begin(), ar.begin() + index);
+        // We static_cast index to a signed type to work around overzealous
+        // compiler warnings about signedness.
+        v.insert(v.end(), ar.begin(),
+                 ar.begin() + static_cast<ptrdiff_t>(index));
       }
       return v;
     }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.cc
index a200efb10b..4ec2023fb8 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.cc
@@ -20,9 +20,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cfloat>  // for DBL_DIG and FLT_DIG
-#include <climits>
 #include <cmath>   // for HUGE_VAL
-#include <cstddef>
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
@@ -30,7 +28,6 @@
 #include <iterator>
 #include <limits>
 #include <system_error>  // NOLINT(build/c++11)
-#include <type_traits>
 #include <utility>
 
 #include "y_absl/base/attributes.h"
@@ -159,71 +156,28 @@ constexpr uint32_t kTwoZeroBytes = 0x0101 * '0';
 constexpr uint64_t kFourZeroBytes = 0x01010101 * '0';
 constexpr uint64_t kEightZeroBytes = 0x0101010101010101ull * '0';
 
-template <typename T>
-constexpr T Pow(T base, uint32_t n) {
-  // Exponentiation by squaring
-  return static_cast<T>((n > 1 ? Pow(base * base, n >> 1) : static_cast<T>(1)) *
-                        ((n & 1) ? base : static_cast<T>(1)));
-}
-
-// Given n, calculates C where the following holds for all 0 <= x < Pow(100, n):
-// x / Pow(10, n) == x * C / Pow(2, n * 10)
-// In other words, it allows us to divide by a power of 10 via a single
-// multiplication and bit shifts, assuming the input will be smaller than the
-// square of that power of 10.
-template <typename T>
-constexpr T ComputePowerOf100DivisionCoefficient(uint32_t n) {
-  if (n > 4) {
-    // This doesn't work for large powers of 100, due to overflow
-    abort();
-  }
-  T denom = 16 - 1;
-  T num = (denom + 1) - 10;
-  T gcd = 3;  // Greatest common divisor of numerator and denominator
-  denom = Pow(denom / gcd, n);
-  num = Pow(num / gcd, 9 * n);
-  T quotient = num / denom;
-  if (num % denom >= denom / 2) {
-    // Round up, since the remainder is more than half the denominator
-    ++quotient;
-  }
-  return quotient;
-}
-
-// * kDivisionBy10Mul / kDivisionBy10Div is a division by 10 for values from 0
-// to 99. It's also a division of a structure [k takes 2 bytes][m takes 2
-// bytes], then * kDivisionBy10Mul / kDivisionBy10Div will be [k / 10][m / 10].
-// It allows parallel division.
-constexpr uint64_t kDivisionBy10Mul =
-    ComputePowerOf100DivisionCoefficient<uint64_t>(1);
-static_assert(kDivisionBy10Mul == 103,
-              "division coefficient for 10 is incorrect");
+// * 103 / 1024 is a division by 10 for values from 0 to 99. It's also a
+// division of a structure [k takes 2 bytes][m takes 2 bytes], then * 103 / 1024
+// will be [k / 10][m / 10]. It allows parallel division.
+constexpr uint64_t kDivisionBy10Mul = 103u;
 constexpr uint64_t kDivisionBy10Div = 1 << 10;
 
-// * kDivisionBy100Mul / kDivisionBy100Div is a division by 100 for values from
-// 0 to 9999.
-constexpr uint64_t kDivisionBy100Mul =
-    ComputePowerOf100DivisionCoefficient<uint64_t>(2);
-static_assert(kDivisionBy100Mul == 10486,
-              "division coefficient for 100 is incorrect");
+// * 10486 / 1048576 is a division by 100 for values from 0 to 9999.
+constexpr uint64_t kDivisionBy100Mul = 10486u;
 constexpr uint64_t kDivisionBy100Div = 1 << 20;
 
-static_assert(ComputePowerOf100DivisionCoefficient<uint64_t>(3) == 1073742,
-              "division coefficient for 1000 is incorrect");
-
-// Same as `PrepareEightDigits`, but produces 2 digits for integers < 100.
-inline uint32_t PrepareTwoDigitsImpl(uint32_t i, bool reversed) {
-  assert(i < 100);
-  uint32_t div10 = (i * kDivisionBy10Mul) / kDivisionBy10Div;
-  uint32_t mod10 = i - 10u * div10;
-  return (div10 << (reversed ? 8 : 0)) + (mod10 << (reversed ? 0 : 8));
-}
-inline uint32_t PrepareTwoDigits(uint32_t i) {
-  return PrepareTwoDigitsImpl(i, false);
+// Encode functions write the ASCII output of input `n` to `out_str`.
+inline char* EncodeHundred(uint32_t n, y_absl::Nonnull<char*> out_str) {
+  int num_digits = static_cast<int>(n - 10) >> 8;
+  uint32_t div10 = (n * kDivisionBy10Mul) / kDivisionBy10Div;
+  uint32_t mod10 = n - 10u * div10;
+  uint32_t base = kTwoZeroBytes + div10 + (mod10 << 8);
+  base >>= num_digits & 8;
+  little_endian::Store16(out_str, static_cast<uint16_t>(base));
+  return out_str + 2 + num_digits;
 }
 
-// Same as `PrepareEightDigits`, but produces 4 digits for integers < 10000.
-inline uint32_t PrepareFourDigitsImpl(uint32_t n, bool reversed) {
+inline char* EncodeTenThousand(uint32_t n, y_absl::Nonnull<char*> out_str) {
   // We split lower 2 digits and upper 2 digits of n into 2 byte consecutive
   // blocks. 123 ->  [\0\1][\0\23]. We divide by 10 both blocks
   // (it's 1 division + zeroing upper bits), and compute modulo 10 as well "in
@@ -231,19 +185,22 @@ inline uint32_t PrepareFourDigitsImpl(uint32_t n, bool reversed) {
   // strip trailing zeros, add ASCII '0000' and return.
   uint32_t div100 = (n * kDivisionBy100Mul) / kDivisionBy100Div;
   uint32_t mod100 = n - 100ull * div100;
-  uint32_t hundreds =
-      (mod100 << (reversed ? 0 : 16)) + (div100 << (reversed ? 16 : 0));
+  uint32_t hundreds = (mod100 << 16) + div100;
   uint32_t tens = (hundreds * kDivisionBy10Mul) / kDivisionBy10Div;
   tens &= (0xFull << 16) | 0xFull;
-  tens = (tens << (reversed ? 8 : 0)) +
-         static_cast<uint32_t>((hundreds - 10ull * tens) << (reversed ? 0 : 8));
-  return tens;
-}
-inline uint32_t PrepareFourDigits(uint32_t n) {
-  return PrepareFourDigitsImpl(n, false);
-}
-inline uint32_t PrepareFourDigitsReversed(uint32_t n) {
-  return PrepareFourDigitsImpl(n, true);
+  tens += (hundreds - 10ull * tens) << 8;
+  Y_ABSL_ASSUME(tens != 0);
+  // The result can contain trailing zero bits, we need to strip them to a first
+  // significant byte in a final representation. For example, for n = 123, we
+  // have tens to have representation \0\1\2\3. We do `& -8` to round
+  // to a multiple to 8 to strip zero bytes, not all zero bits.
+  // countr_zero to help.
+  // 0 minus 8 to make MSVC happy.
+  uint32_t zeroes = static_cast<uint32_t>(y_absl::countr_zero(tens)) & (0 - 8u);
+  tens += kFourZeroBytes;
+  tens >>= zeroes;
+  little_endian::Store32(out_str, tens);
+  return out_str + sizeof(tens) - zeroes / 8;
 }
 
 // Helper function to produce an ASCII representation of `i`.
@@ -259,309 +216,126 @@ inline uint32_t PrepareFourDigitsReversed(uint32_t n) {
 //  // Note two leading zeros:
 //  EXPECT_EQ(y_absl::string_view(ascii, 8), "00102030");
 //
-// If `Reversed` is set to true, the result becomes reversed to "03020100".
-//
 // Pre-condition: `i` must be less than 100000000.
-inline uint64_t PrepareEightDigitsImpl(uint32_t i, bool reversed) {
+inline uint64_t PrepareEightDigits(uint32_t i) {
   Y_ABSL_ASSUME(i < 10000'0000);
   // Prepare 2 blocks of 4 digits "in parallel".
   uint32_t hi = i / 10000;
   uint32_t lo = i % 10000;
-  uint64_t merged = (uint64_t{hi} << (reversed ? 32 : 0)) |
-                    (uint64_t{lo} << (reversed ? 0 : 32));
+  uint64_t merged = hi | (uint64_t{lo} << 32);
   uint64_t div100 = ((merged * kDivisionBy100Mul) / kDivisionBy100Div) &
                     ((0x7Full << 32) | 0x7Full);
   uint64_t mod100 = merged - 100ull * div100;
-  uint64_t hundreds =
-      (mod100 << (reversed ? 0 : 16)) + (div100 << (reversed ? 16 : 0));
+  uint64_t hundreds = (mod100 << 16) + div100;
   uint64_t tens = (hundreds * kDivisionBy10Mul) / kDivisionBy10Div;
   tens &= (0xFull << 48) | (0xFull << 32) | (0xFull << 16) | 0xFull;
-  tens = (tens << (reversed ? 8 : 0)) +
-         ((hundreds - 10ull * tens) << (reversed ? 0 : 8));
+  tens += (hundreds - 10ull * tens) << 8;
   return tens;
 }
-inline uint64_t PrepareEightDigits(uint32_t i) {
-  return PrepareEightDigitsImpl(i, false);
-}
-inline uint64_t PrepareEightDigitsReversed(uint32_t i) {
-  return PrepareEightDigitsImpl(i, true);
-}
 
-template <typename T, typename BackwardIt>
-class FastUIntToStringConverter {
-  static_assert(
-      std::is_same<T, decltype(+std::declval<T>())>::value,
-      "to avoid code bloat, only instantiate this for int and larger types");
-  static_assert(std::is_unsigned<T>::value,
-                "this class is only for unsigned types");
-
- public:
-  // Outputs the given number backward (like with std::copy_backward),
-  // starting from the end of the string.
-  // The number of digits in the number must have been already measured and
-  // passed *exactly*, otherwise the behavior is undefined.
-  // (This is an optimization, as calculating the number of digits again would
-  // slow down the hot path.)
-  // Returns an iterator to the start of the suffix that was appended.
-  static BackwardIt FastIntToBufferBackward(T v, BackwardIt end) {
-    // THIS IS A HOT FUNCTION with a very deliberate structure to exploit branch
-    // prediction and shorten the critical path for smaller numbers.
-    // Do not move around the if/else blocks or attempt to simplify it
-    // without benchmarking any changes.
-
-    if (v < 10) {
-      goto AT_LEAST_1 /* NOTE: mandatory for the 0 case */;
-    }
-    if (v < 1000) {
-      goto AT_LEAST_10;
-    }
-    if (v < 10000000) {
-      goto AT_LEAST_1000;
-    }
-
-    if (v >= 100000000 / 10) {
-      if (v >= 10000000000000000 / 10) {
-        DoFastIntToBufferBackward<8>(v, end);
-      }
-      DoFastIntToBufferBackward<8>(v, end);
-    }
-
-    if (v >= 10000 / 10) {
-    AT_LEAST_1000:
-      DoFastIntToBufferBackward<4>(v, end);
-    }
-
-    if (v >= 100 / 10) {
-    AT_LEAST_10:
-      DoFastIntToBufferBackward<2>(v, end);
-    }
-
-    if (v >= 10 / 10) {
-    AT_LEAST_1:
-      end = DoFastIntToBufferBackward(v, end, std::integral_constant<int, 1>());
-    }
-    return end;
+inline Y_ABSL_ATTRIBUTE_ALWAYS_INLINE y_absl::Nonnull<char*> EncodeFullU32(
+    uint32_t n, y_absl::Nonnull<char*> out_str) {
+  if (n < 10) {
+    *out_str = static_cast<char>('0' + n);
+    return out_str + 1;
   }
-
- private:
-  // Only assume pointers are contiguous for now. String and vector iterators
-  // could be special-cased as well, but there's no need for them here.
-  // With C++20 we can probably switch to std::contiguous_iterator_tag.
-  static constexpr bool kIsContiguousIterator =
-      std::is_pointer<BackwardIt>::value;
-
-  template <int Exponent>
-  static void DoFastIntToBufferBackward(T& v, BackwardIt& end) {
-    constexpr T kModulus = Pow<T>(10, Exponent);
-    T remainder = static_cast<T>(v % kModulus);
-    v = static_cast<T>(v / kModulus);
-    end = DoFastIntToBufferBackward(remainder, end,
-                                    std::integral_constant<int, Exponent>());
-  }
-
-  static BackwardIt DoFastIntToBufferBackward(const T&, BackwardIt end,
-                                              std::integral_constant<int, 0>) {
-    return end;
-  }
-
-  static BackwardIt DoFastIntToBufferBackward(T v, BackwardIt end,
-                                              std::integral_constant<int, 1>) {
-    *--end = static_cast<char>('0' + v);
-    return DoFastIntToBufferBackward(v, end, std::integral_constant<int, 0>());
-  }
-
-  static BackwardIt DoFastIntToBufferBackward(T v, BackwardIt end,
-                                              std::integral_constant<int, 4>) {
-    if (kIsContiguousIterator) {
-      const uint32_t digits =
-          PrepareFourDigits(static_cast<uint32_t>(v)) + kFourZeroBytes;
-      end -= sizeof(digits);
-      little_endian::Store32(&*end, digits);
-    } else {
-      uint32_t digits =
-          PrepareFourDigitsReversed(static_cast<uint32_t>(v)) + kFourZeroBytes;
-      for (size_t i = 0; i < sizeof(digits); ++i) {
-        *--end = static_cast<char>(digits);
-        digits >>= CHAR_BIT;
-      }
-    }
-    return end;
+  if (n < 100'000'000) {
+    uint64_t bottom = PrepareEightDigits(n);
+    Y_ABSL_ASSUME(bottom != 0);
+    // 0 minus 8 to make MSVC happy.
+    uint32_t zeroes =
+        static_cast<uint32_t>(y_absl::countr_zero(bottom)) & (0 - 8u);
+    little_endian::Store64(out_str, (bottom + kEightZeroBytes) >> zeroes);
+    return out_str + sizeof(bottom) - zeroes / 8;
   }
-
-  static BackwardIt DoFastIntToBufferBackward(T v, BackwardIt end,
-                                              std::integral_constant<int, 8>) {
-    if (kIsContiguousIterator) {
-      const uint64_t digits =
-          PrepareEightDigits(static_cast<uint32_t>(v)) + kEightZeroBytes;
-      end -= sizeof(digits);
-      little_endian::Store64(&*end, digits);
-    } else {
-      uint64_t digits = PrepareEightDigitsReversed(static_cast<uint32_t>(v)) +
-                        kEightZeroBytes;
-      for (size_t i = 0; i < sizeof(digits); ++i) {
-        *--end = static_cast<char>(digits);
-        digits >>= CHAR_BIT;
-      }
-    }
-    return end;
-  }
-
-  template <int Digits>
-  static BackwardIt DoFastIntToBufferBackward(
-      T v, BackwardIt end, std::integral_constant<int, Digits>) {
-    constexpr int kLogModulus = Digits - Digits / 2;
-    constexpr T kModulus = Pow(static_cast<T>(10), kLogModulus);
-    bool is_safe_to_use_division_trick = Digits <= 8;
-    T quotient, remainder;
-    if (is_safe_to_use_division_trick) {
-      constexpr uint64_t kCoefficient =
-          ComputePowerOf100DivisionCoefficient<uint64_t>(kLogModulus);
-      quotient = (v * kCoefficient) >> (10 * kLogModulus);
-      remainder = v - quotient * kModulus;
-    } else {
-      quotient = v / kModulus;
-      remainder = v % kModulus;
-    }
-    end = DoFastIntToBufferBackward(remainder, end,
-                                    std::integral_constant<int, kLogModulus>());
-    return DoFastIntToBufferBackward(
-        quotient, end, std::integral_constant<int, Digits - kLogModulus>());
-  }
-};
-
-// Returns an iterator to the start of the suffix that was appended
-template <typename T, typename BackwardIt>
-std::enable_if_t<std::is_unsigned<T>::value, BackwardIt>
-DoFastIntToBufferBackward(T v, BackwardIt end, uint32_t digits) {
-  using PromotedT = std::decay_t<decltype(+v)>;
-  using Converter = FastUIntToStringConverter<PromotedT, BackwardIt>;
-  (void)digits;
-  return Converter().FastIntToBufferBackward(v, end);
+  uint32_t div08 = n / 100'000'000;
+  uint32_t mod08 = n % 100'000'000;
+  uint64_t bottom = PrepareEightDigits(mod08) + kEightZeroBytes;
+  out_str = EncodeHundred(div08, out_str);
+  little_endian::Store64(out_str, bottom);
+  return out_str + sizeof(bottom);
 }
 
-template <typename T, typename BackwardIt>
-std::enable_if_t<std::is_signed<T>::value, BackwardIt>
-DoFastIntToBufferBackward(T v, BackwardIt end, uint32_t digits) {
-  if (y_absl::numbers_internal::IsNegative(v)) {
-    // Store the minus sign *before* we produce the number itself, not after.
-    // This gets us a tail call.
-    end[-static_cast<ptrdiff_t>(digits) - 1] = '-';
+inline Y_ABSL_ATTRIBUTE_ALWAYS_INLINE char* EncodeFullU64(uint64_t i,
+                                                        char* buffer) {
+  if (i <= std::numeric_limits<uint32_t>::max()) {
+    return EncodeFullU32(static_cast<uint32_t>(i), buffer);
   }
-  return DoFastIntToBufferBackward(
-      y_absl::numbers_internal::UnsignedAbsoluteValue(v), end, digits);
-}
-
-template <class T>
-std::enable_if_t<std::is_integral<T>::value, int>
-GetNumDigitsOrNegativeIfNegativeImpl(T v) {
-  const auto /* either bool or std::false_type */ is_negative =
-      y_absl::numbers_internal::IsNegative(v);
-  const int digits = static_cast<int>(y_absl::numbers_internal::Base10Digits(
-      y_absl::numbers_internal::UnsignedAbsoluteValue(v)));
-  return is_negative ? ~digits : digits;
+  uint32_t mod08;
+  if (i < 1'0000'0000'0000'0000ull) {
+    uint32_t div08 = static_cast<uint32_t>(i / 100'000'000ull);
+    mod08 =  static_cast<uint32_t>(i % 100'000'000ull);
+    buffer = EncodeFullU32(div08, buffer);
+  } else {
+    uint64_t div08 = i / 100'000'000ull;
+    mod08 =  static_cast<uint32_t>(i % 100'000'000ull);
+    uint32_t div016 = static_cast<uint32_t>(div08 / 100'000'000ull);
+    uint32_t div08mod08 = static_cast<uint32_t>(div08 % 100'000'000ull);
+    uint64_t mid_result = PrepareEightDigits(div08mod08) + kEightZeroBytes;
+    buffer = EncodeTenThousand(div016, buffer);
+    little_endian::Store64(buffer, mid_result);
+    buffer += sizeof(mid_result);
+  }
+  uint64_t mod_result = PrepareEightDigits(mod08) + kEightZeroBytes;
+  little_endian::Store64(buffer, mod_result);
+  return buffer + sizeof(mod_result);
 }
 
 }  // namespace
 
 void numbers_internal::PutTwoDigits(uint32_t i, y_absl::Nonnull<char*> buf) {
-  little_endian::Store16(
-      buf, static_cast<uint16_t>(PrepareTwoDigits(i) + kTwoZeroBytes));
+  assert(i < 100);
+  uint32_t base = kTwoZeroBytes;
+  uint32_t div10 = (i * kDivisionBy10Mul) / kDivisionBy10Div;
+  uint32_t mod10 = i - 10u * div10;
+  base += div10 + (mod10 << 8);
+  little_endian::Store16(buf, static_cast<uint16_t>(base));
 }
 
 y_absl::Nonnull<char*> numbers_internal::FastIntToBuffer(
-    uint32_t i, y_absl::Nonnull<char*> buffer) {
-  const uint32_t digits = y_absl::numbers_internal::Base10Digits(i);
-  buffer += digits;
-  *buffer = '\0';  // We're going backward, so store this first
-  FastIntToBufferBackward(i, buffer, digits);
-  return buffer;
+    uint32_t n, y_absl::Nonnull<char*> out_str) {
+  out_str = EncodeFullU32(n, out_str);
+  *out_str = '\0';
+  return out_str;
 }
 
 y_absl::Nonnull<char*> numbers_internal::FastIntToBuffer(
     int32_t i, y_absl::Nonnull<char*> buffer) {
-  buffer += static_cast<int>(i < 0);
-  uint32_t digits = y_absl::numbers_internal::Base10Digits(
-      y_absl::numbers_internal::UnsignedAbsoluteValue(i));
-  buffer += digits;
-  *buffer = '\0';  // We're going backward, so store this first
-  FastIntToBufferBackward(i, buffer, digits);
+  uint32_t u = static_cast<uint32_t>(i);
+  if (i < 0) {
+    *buffer++ = '-';
+    // We need to do the negation in modular (i.e., "unsigned")
+    // arithmetic; MSVC++ apparently warns for plain "-u", so
+    // we write the equivalent expression "0 - u" instead.
+    u = 0 - u;
+  }
+  buffer = EncodeFullU32(u, buffer);
+  *buffer = '\0';
   return buffer;
 }
 
 y_absl::Nonnull<char*> numbers_internal::FastIntToBuffer(
     uint64_t i, y_absl::Nonnull<char*> buffer) {
-  uint32_t digits = y_absl::numbers_internal::Base10Digits(i);
-  buffer += digits;
-  *buffer = '\0';  // We're going backward, so store this first
-  FastIntToBufferBackward(i, buffer, digits);
+  buffer = EncodeFullU64(i, buffer);
+  *buffer = '\0';
   return buffer;
 }
 
 y_absl::Nonnull<char*> numbers_internal::FastIntToBuffer(
     int64_t i, y_absl::Nonnull<char*> buffer) {
-  buffer += static_cast<int>(i < 0);
-  uint32_t digits = y_absl::numbers_internal::Base10Digits(
-      y_absl::numbers_internal::UnsignedAbsoluteValue(i));
-  buffer += digits;
-  *buffer = '\0';  // We're going backward, so store this first
-  FastIntToBufferBackward(i, buffer, digits);
+  uint64_t u = static_cast<uint64_t>(i);
+  if (i < 0) {
+    *buffer++ = '-';
+    // We need to do the negation in modular (i.e., "unsigned")
+    // arithmetic; MSVC++ apparently warns for plain "-u", so
+    // we write the equivalent expression "0 - u" instead.
+    u = 0 - u;
+  }
+  buffer = EncodeFullU64(u, buffer);
+  *buffer = '\0';
   return buffer;
 }
 
-y_absl::Nonnull<char*> numbers_internal::FastIntToBufferBackward(
-    uint32_t i, y_absl::Nonnull<char*> buffer_end, uint32_t exact_digit_count) {
-  return DoFastIntToBufferBackward(i, buffer_end, exact_digit_count);
-}
-
-y_absl::Nonnull<char*> numbers_internal::FastIntToBufferBackward(
-    int32_t i, y_absl::Nonnull<char*> buffer_end, uint32_t exact_digit_count) {
-  return DoFastIntToBufferBackward(i, buffer_end, exact_digit_count);
-}
-
-y_absl::Nonnull<char*> numbers_internal::FastIntToBufferBackward(
-    uint64_t i, y_absl::Nonnull<char*> buffer_end, uint32_t exact_digit_count) {
-  return DoFastIntToBufferBackward(i, buffer_end, exact_digit_count);
-}
-
-y_absl::Nonnull<char*> numbers_internal::FastIntToBufferBackward(
-    int64_t i, y_absl::Nonnull<char*> buffer_end, uint32_t exact_digit_count) {
-  return DoFastIntToBufferBackward(i, buffer_end, exact_digit_count);
-}
-
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(signed char v) {
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(unsigned char v) {
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(short v) {  // NOLINT
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(
-    unsigned short v) {  // NOLINT
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(int v) {
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(unsigned int v) {
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(long v) {  // NOLINT
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(
-    unsigned long v) {  // NOLINT
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(long long v) {  // NOLINT
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-int numbers_internal::GetNumDigitsOrNegativeIfNegative(
-    unsigned long long v) {  // NOLINT
-  return GetNumDigitsOrNegativeIfNegativeImpl(v);
-}
-
 // Given a 128-bit number expressed as a pair of uint64_t, high half first,
 // return that number multiplied by the given 32-bit value.  If the result is
 // too large to fit in a 128-bit number, divide it by 2 until it fits.
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.h
index 737a0f0308..483afc26e1 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/numbers.h
@@ -32,7 +32,6 @@
 #endif
 
 #include <cstddef>
-#include <cstdint>
 #include <cstdlib>
 #include <cstring>
 #include <ctime>
@@ -40,12 +39,10 @@
 #include <util/generic/string.h>
 #include <type_traits>
 
-#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/endian.h"
 #include "y_absl/base/macros.h"
 #include "y_absl/base/nullability.h"
-#include "y_absl/base/optimization.h"
 #include "y_absl/base/port.h"
 #include "y_absl/numeric/bits.h"
 #include "y_absl/numeric/int128.h"
@@ -161,96 +158,6 @@ bool safe_strtou128_base(y_absl::string_view text,
 static const int kFastToBufferSize = 32;
 static const int kSixDigitsToBufferSize = 16;
 
-template <class T>
-std::enable_if_t<!std::is_unsigned<T>::value, bool> IsNegative(const T& v) {
-  return v < T();
-}
-
-template <class T>
-std::enable_if_t<std::is_unsigned<T>::value, std::false_type> IsNegative(
-    const T&) {
-  // The integer is unsigned, so return a compile-time constant.
-  // This can help the optimizer avoid having to prove bool to be false later.
-  return std::false_type();
-}
-
-template <class T>
-std::enable_if_t<std::is_unsigned<std::decay_t<T>>::value, T&&>
-UnsignedAbsoluteValue(T&& v Y_ABSL_ATTRIBUTE_LIFETIME_BOUND) {
-  // The value is unsigned; just return the original.
-  return std::forward<T>(v);
-}
-
-template <class T>
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION
-    std::enable_if_t<!std::is_unsigned<T>::value, std::make_unsigned_t<T>>
-    UnsignedAbsoluteValue(T v) {
-  using U = std::make_unsigned_t<T>;
-  return IsNegative(v) ? U() - static_cast<U>(v) : static_cast<U>(v);
-}
-
-// Returns the number of base-10 digits in the given number.
-// Note that this strictly counts digits. It does not count the sign.
-// The `initial_digits` parameter is the starting point, which is normally equal
-// to 1 because the number of digits in 0 is 1 (a special case).
-// However, callers may e.g. wish to change it to 2 to account for the sign.
-template <typename T>
-std::enable_if_t<std::is_unsigned<T>::value, uint32_t> Base10Digits(
-    T v, const uint32_t initial_digits = 1) {
-  uint32_t r = initial_digits;
-  // If code size becomes an issue, the 'if' stage can be removed for a minor
-  // performance loss.
-  for (;;) {
-    if (Y_ABSL_PREDICT_TRUE(v < 10 * 10)) {
-      r += (v >= 10);
-      break;
-    }
-    if (Y_ABSL_PREDICT_TRUE(v < 1000 * 10)) {
-      r += (v >= 1000) + 2;
-      break;
-    }
-    if (Y_ABSL_PREDICT_TRUE(v < 100000 * 10)) {
-      r += (v >= 100000) + 4;
-      break;
-    }
-    r += 6;
-    v = static_cast<T>(v / 1000000);
-  }
-  return r;
-}
-
-template <typename T>
-std::enable_if_t<std::is_signed<T>::value, uint32_t> Base10Digits(
-    T v, uint32_t r = 1) {
-  // Branchlessly add 1 to account for a minus sign.
-  r += static_cast<uint32_t>(IsNegative(v));
-  return Base10Digits(UnsignedAbsoluteValue(v), r);
-}
-
-// These functions return the number of base-10 digits, but multiplied by -1 if
-// the input itself is negative. This is handy and efficient for later usage,
-// since the bitwise complement of the result becomes equal to the number of
-// characters required.
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    signed char v);
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    unsigned char v);
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    short v);  // NOLINT
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    unsigned short v);  // NOLINT
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(int v);
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    unsigned int v);
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    long v);  // NOLINT
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    unsigned long v);  // NOLINT
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    long long v);  // NOLINT
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
-    unsigned long long v);  // NOLINT
-
 // Helper function for fast formatting of floating-point values.
 // The result is the same as printf's "%g", a.k.a. "%.6g"; that is, six
 // significant digits are returned, trailing zeros are removed, and numbers
@@ -259,18 +166,24 @@ Y_ABSL_ATTRIBUTE_CONST_FUNCTION int GetNumDigitsOrNegativeIfNegative(
 // Required buffer size is `kSixDigitsToBufferSize`.
 size_t SixDigitsToBuffer(double d, y_absl::Nonnull<char*> buffer);
 
-// All of these functions take an output buffer
+// WARNING: These functions may write more characters than necessary, because
+// they are intended for speed. All functions take an output buffer
 // as an argument and return a pointer to the last byte they wrote, which is the
 // terminating '\0'. At most `kFastToBufferSize` bytes are written.
-y_absl::Nonnull<char*> FastIntToBuffer(int32_t i, y_absl::Nonnull<char*> buffer);
-y_absl::Nonnull<char*> FastIntToBuffer(uint32_t i, y_absl::Nonnull<char*> buffer);
-y_absl::Nonnull<char*> FastIntToBuffer(int64_t i, y_absl::Nonnull<char*> buffer);
-y_absl::Nonnull<char*> FastIntToBuffer(uint64_t i, y_absl::Nonnull<char*> buffer);
+y_absl::Nonnull<char*> FastIntToBuffer(int32_t i, y_absl::Nonnull<char*> buffer)
+    Y_ABSL_INTERNAL_NEED_MIN_SIZE(buffer, kFastToBufferSize);
+y_absl::Nonnull<char*> FastIntToBuffer(uint32_t n, y_absl::Nonnull<char*> out_str)
+    Y_ABSL_INTERNAL_NEED_MIN_SIZE(out_str, kFastToBufferSize);
+y_absl::Nonnull<char*> FastIntToBuffer(int64_t i, y_absl::Nonnull<char*> buffer)
+    Y_ABSL_INTERNAL_NEED_MIN_SIZE(buffer, kFastToBufferSize);
+y_absl::Nonnull<char*> FastIntToBuffer(uint64_t i, y_absl::Nonnull<char*> buffer)
+    Y_ABSL_INTERNAL_NEED_MIN_SIZE(buffer, kFastToBufferSize);
 
 // For enums and integer types that are not an exact match for the types above,
 // use templates to call the appropriate one of the four overloads above.
 template <typename int_type>
-y_absl::Nonnull<char*> FastIntToBuffer(int_type i, y_absl::Nonnull<char*> buffer) {
+y_absl::Nonnull<char*> FastIntToBuffer(int_type i, y_absl::Nonnull<char*> buffer)
+    Y_ABSL_INTERNAL_NEED_MIN_SIZE(buffer, kFastToBufferSize) {
   static_assert(sizeof(i) <= 64 / 8,
                 "FastIntToBuffer works only with 64-bit-or-less integers.");
   // TODO(jorg): This signed-ness check is used because it works correctly
@@ -294,58 +207,6 @@ y_absl::Nonnull<char*> FastIntToBuffer(int_type i, y_absl::Nonnull<char*> buffer
   }
 }
 
-// These functions do NOT add any null-terminator.
-// They return a pointer to the beginning of the written string.
-// The digit counts provided must *exactly* match the number of base-10 digits
-// in the number, or the behavior is undefined.
-// (i.e. do NOT count the minus sign, or over- or under-count the digits.)
-y_absl::Nonnull<char*> FastIntToBufferBackward(int32_t i,
-                                             y_absl::Nonnull<char*> buffer_end,
-                                             uint32_t exact_digit_count);
-y_absl::Nonnull<char*> FastIntToBufferBackward(uint32_t i,
-                                             y_absl::Nonnull<char*> buffer_end,
-                                             uint32_t exact_digit_count);
-y_absl::Nonnull<char*> FastIntToBufferBackward(int64_t i,
-                                             y_absl::Nonnull<char*> buffer_end,
-                                             uint32_t exact_digit_count);
-y_absl::Nonnull<char*> FastIntToBufferBackward(uint64_t i,
-                                             y_absl::Nonnull<char*> buffer_end,
-                                             uint32_t exact_digit_count);
-
-// For enums and integer types that are not an exact match for the types above,
-// use templates to call the appropriate one of the four overloads above.
-template <typename int_type>
-y_absl::Nonnull<char*> FastIntToBufferBackward(int_type i,
-                                             y_absl::Nonnull<char*> buffer_end,
-                                             uint32_t exact_digit_count) {
-  static_assert(
-      sizeof(i) <= 64 / 8,
-      "FastIntToBufferBackward works only with 64-bit-or-less integers.");
-  // This signed-ness check is used because it works correctly
-  // with enums, and it also serves to check that int_type is not a pointer.
-  // If one day something like std::is_signed<enum E> works, switch to it.
-  // These conditions are constexpr bools to suppress MSVC warning C4127.
-  constexpr bool kIsSigned = static_cast<int_type>(1) - 2 < 0;
-  constexpr bool kUse64Bit = sizeof(i) > 32 / 8;
-  if (kIsSigned) {
-    if (kUse64Bit) {
-      return FastIntToBufferBackward(static_cast<int64_t>(i), buffer_end,
-                                     exact_digit_count);
-    } else {
-      return FastIntToBufferBackward(static_cast<int32_t>(i), buffer_end,
-                                     exact_digit_count);
-    }
-  } else {
-    if (kUse64Bit) {
-      return FastIntToBufferBackward(static_cast<uint64_t>(i), buffer_end,
-                                     exact_digit_count);
-    } else {
-      return FastIntToBufferBackward(static_cast<uint32_t>(i), buffer_end,
-                                     exact_digit_count);
-    }
-  }
-}
-
 // Implementation of SimpleAtoi, generalized to support arbitrary base (used
 // with base different from 10 elsewhere in Abseil implementation).
 template <typename int_type>
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.cc
index 2f74723a54..0799908247 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.cc
@@ -20,19 +20,18 @@
 #include <cstdint>
 #include <cstring>
 #include <initializer_list>
+#include <limits>
 #include <util/generic/string.h>
-#include <type_traits>
 
 #include "y_absl/base/config.h"
+#include "y_absl/base/internal/raw_logging.h"
 #include "y_absl/base/nullability.h"
 #include "y_absl/strings/internal/resize_uninitialized.h"
-#include "y_absl/strings/numbers.h"
 #include "y_absl/strings/string_view.h"
 
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
 
-
 // ----------------------------------------------------------------------
 // StrCat()
 //    This merges the given strings or integers, with no delimiter. This
@@ -43,7 +42,8 @@ Y_ABSL_NAMESPACE_BEGIN
 namespace {
 // Append is merely a version of memcpy that returns the address of the byte
 // after the area just overwritten.
-y_absl::Nonnull<char*> Append(y_absl::Nonnull<char*> out, const AlphaNum& x) {
+inline y_absl::Nonnull<char*> Append(y_absl::Nonnull<char*> out,
+                                   const AlphaNum& x) {
   // memcpy is allowed to overwrite arbitrary memory, so doing this after the
   // call would force an extra fetch of x.size().
   char* after = out + x.size();
@@ -53,12 +53,23 @@ y_absl::Nonnull<char*> Append(y_absl::Nonnull<char*> out, const AlphaNum& x) {
   return after;
 }
 
+inline void STLStringAppendUninitializedAmortized(TString* dest,
+                                                  size_t to_append) {
+  strings_internal::AppendUninitializedTraits<TString>::Append(dest,
+                                                                   to_append);
+}
 }  // namespace
 
 TString StrCat(const AlphaNum& a, const AlphaNum& b) {
   TString result;
-  y_absl::strings_internal::STLStringResizeUninitialized(&result,
-                                                       a.size() + b.size());
+  // Use uint64_t to prevent size_t overflow. We assume it is not possible for
+  // in memory strings to overflow a uint64_t.
+  constexpr uint64_t kMaxSize = uint64_t{std::numeric_limits<size_t>::max()};
+  const uint64_t result_size =
+      static_cast<uint64_t>(a.size()) + static_cast<uint64_t>(b.size());
+  Y_ABSL_INTERNAL_CHECK(result_size <= kMaxSize, "size_t overflow");
+  y_absl::strings_internal::STLStringResizeUninitialized(
+      &result, static_cast<size_t>(result_size));
   char* const begin = &result[0];
   char* out = begin;
   out = Append(out, a);
@@ -69,8 +80,15 @@ TString StrCat(const AlphaNum& a, const AlphaNum& b) {
 
 TString StrCat(const AlphaNum& a, const AlphaNum& b, const AlphaNum& c) {
   TString result;
+  // Use uint64_t to prevent size_t overflow. We assume it is not possible for
+  // in memory strings to overflow a uint64_t.
+  constexpr uint64_t kMaxSize = uint64_t{std::numeric_limits<size_t>::max()};
+  const uint64_t result_size = static_cast<uint64_t>(a.size()) +
+                               static_cast<uint64_t>(b.size()) +
+                               static_cast<uint64_t>(c.size());
+  Y_ABSL_INTERNAL_CHECK(result_size <= kMaxSize, "size_t overflow");
   strings_internal::STLStringResizeUninitialized(
-      &result, a.size() + b.size() + c.size());
+      &result, static_cast<size_t>(result_size));
   char* const begin = &result[0];
   char* out = begin;
   out = Append(out, a);
@@ -83,8 +101,16 @@ TString StrCat(const AlphaNum& a, const AlphaNum& b, const AlphaNum& c) {
 TString StrCat(const AlphaNum& a, const AlphaNum& b, const AlphaNum& c,
                    const AlphaNum& d) {
   TString result;
+  // Use uint64_t to prevent size_t overflow. We assume it is not possible for
+  // in memory strings to overflow a uint64_t.
+  constexpr uint64_t kMaxSize = uint64_t{std::numeric_limits<size_t>::max()};
+  const uint64_t result_size = static_cast<uint64_t>(a.size()) +
+                               static_cast<uint64_t>(b.size()) +
+                               static_cast<uint64_t>(c.size()) +
+                               static_cast<uint64_t>(d.size());
+  Y_ABSL_INTERNAL_CHECK(result_size <= kMaxSize, "size_t overflow");
   strings_internal::STLStringResizeUninitialized(
-      &result, a.size() + b.size() + c.size() + d.size());
+      &result, static_cast<size_t>(result_size));
   char* const begin = &result[0];
   char* out = begin;
   out = Append(out, a);
@@ -98,135 +124,18 @@ TString StrCat(const AlphaNum& a, const AlphaNum& b, const AlphaNum& c,
 namespace strings_internal {
 
 // Do not call directly - these are not part of the public API.
-void STLStringAppendUninitializedAmortized(TString* dest,
-                                           size_t to_append) {
-  strings_internal::AppendUninitializedTraits<TString>::Append(dest,
-                                                                   to_append);
-}
-
-template <typename Integer>
-std::enable_if_t<std::is_integral<Integer>::value, TString> IntegerToString(
-    Integer i) {
-  TString str;
-  const auto /* either bool or std::false_type */ is_negative =
-      y_absl::numbers_internal::IsNegative(i);
-  const uint32_t digits = y_absl::numbers_internal::Base10Digits(
-      y_absl::numbers_internal::UnsignedAbsoluteValue(i));
-  y_absl::strings_internal::STLStringResizeUninitialized(
-      &str, digits + static_cast<uint32_t>(is_negative));
-  y_absl::numbers_internal::FastIntToBufferBackward(i, &str[str.size()], digits);
-  return str;
-}
-
-template <>
-TString IntegerToString(long i) {  // NOLINT
-  if (sizeof(i) <= sizeof(int)) {
-    return IntegerToString(static_cast<int>(i));
-  } else {
-    return IntegerToString(static_cast<long long>(i));  // NOLINT
-  }
-}
-
-template <>
-TString IntegerToString(unsigned long i) {  // NOLINT
-  if (sizeof(i) <= sizeof(unsigned int)) {
-    return IntegerToString(static_cast<unsigned int>(i));
-  } else {
-    return IntegerToString(static_cast<unsigned long long>(i));  // NOLINT
-  }
-}
-
-template <typename Float>
-std::enable_if_t<std::is_floating_point<Float>::value, TString>
-FloatToString(Float f) {
-  TString result;
-  strings_internal::STLStringResizeUninitialized(
-      &result, numbers_internal::kSixDigitsToBufferSize);
-  char* start = &result[0];
-  result.erase(numbers_internal::SixDigitsToBuffer(f, start));
-  return result;
-}
-
-TString SingleArgStrCat(int x) { return IntegerToString(x); }
-TString SingleArgStrCat(unsigned int x) { return IntegerToString(x); }
-// NOLINTNEXTLINE
-TString SingleArgStrCat(long x) { return IntegerToString(x); }
-// NOLINTNEXTLINE
-TString SingleArgStrCat(unsigned long x) { return IntegerToString(x); }
-// NOLINTNEXTLINE
-TString SingleArgStrCat(long long x) { return IntegerToString(x); }
-// NOLINTNEXTLINE
-TString SingleArgStrCat(unsigned long long x) { return IntegerToString(x); }
-TString SingleArgStrCat(float x) { return FloatToString(x); }
-TString SingleArgStrCat(double x) { return FloatToString(x); }
-
-template <class Integer>
-std::enable_if_t<std::is_integral<Integer>::value, void> AppendIntegerToString(
-    TString& str, Integer i) {
-  const auto /* either bool or std::false_type */ is_negative =
-      y_absl::numbers_internal::IsNegative(i);
-  const uint32_t digits = y_absl::numbers_internal::Base10Digits(
-      y_absl::numbers_internal::UnsignedAbsoluteValue(i));
-  y_absl::strings_internal::STLStringAppendUninitializedAmortized(
-      &str, digits + static_cast<uint32_t>(is_negative));
-  y_absl::numbers_internal::FastIntToBufferBackward(i, &str[str.size()], digits);
-}
-
-template <>
-void AppendIntegerToString(TString& str, long i) {  // NOLINT
-  if (sizeof(i) <= sizeof(int)) {
-    return AppendIntegerToString(str, static_cast<int>(i));
-  } else {
-    return AppendIntegerToString(str, static_cast<long long>(i));  // NOLINT
-  }
-}
-
-template <>
-void AppendIntegerToString(TString& str,
-                           unsigned long i) {  // NOLINT
-  if (sizeof(i) <= sizeof(unsigned int)) {
-    return AppendIntegerToString(str, static_cast<unsigned int>(i));
-  } else {
-    return AppendIntegerToString(str,
-                                 static_cast<unsigned long long>(i));  // NOLINT
-  }
-}
-
-// `SingleArgStrAppend` overloads are defined here for the same reasons as with
-// `SingleArgStrCat` above.
-void SingleArgStrAppend(TString& str, int x) {
-  return AppendIntegerToString(str, x);
-}
-
-void SingleArgStrAppend(TString& str, unsigned int x) {
-  return AppendIntegerToString(str, x);
-}
-
-// NOLINTNEXTLINE
-void SingleArgStrAppend(TString& str, long x) {
-  return AppendIntegerToString(str, x);
-}
-
-// NOLINTNEXTLINE
-void SingleArgStrAppend(TString& str, unsigned long x) {
-  return AppendIntegerToString(str, x);
-}
-
-// NOLINTNEXTLINE
-void SingleArgStrAppend(TString& str, long long x) {
-  return AppendIntegerToString(str, x);
-}
-
-// NOLINTNEXTLINE
-void SingleArgStrAppend(TString& str, unsigned long long x) {
-  return AppendIntegerToString(str, x);
-}
-
 TString CatPieces(std::initializer_list<y_absl::string_view> pieces) {
   TString result;
-  size_t total_size = 0;
-  for (y_absl::string_view piece : pieces) total_size += piece.size();
-  strings_internal::STLStringResizeUninitialized(&result, total_size);
+  // Use uint64_t to prevent size_t overflow. We assume it is not possible for
+  // in memory strings to overflow a uint64_t.
+  constexpr uint64_t kMaxSize = uint64_t{std::numeric_limits<size_t>::max()};
+  uint64_t total_size = 0;
+  for (y_absl::string_view piece : pieces) {
+    total_size += piece.size();
+  }
+  Y_ABSL_INTERNAL_CHECK(total_size <= kMaxSize, "size_t overflow");
+  strings_internal::STLStringResizeUninitialized(
+      &result, static_cast<size_t>(total_size));
 
   char* const begin = &result[0];
   char* out = begin;
@@ -258,7 +167,7 @@ void AppendPieces(y_absl::Nonnull<TString*> dest,
     ASSERT_NO_OVERLAP(*dest, piece);
     to_append += piece.size();
   }
-  strings_internal::STLStringAppendUninitializedAmortized(dest, to_append);
+  STLStringAppendUninitializedAmortized(dest, to_append);
 
   char* const begin = &(*dest)[0];
   char* out = begin + old_size;
@@ -277,7 +186,7 @@ void AppendPieces(y_absl::Nonnull<TString*> dest,
 void StrAppend(y_absl::Nonnull<TString*> dest, const AlphaNum& a) {
   ASSERT_NO_OVERLAP(*dest, a);
   TString::size_type old_size = dest->size();
-  strings_internal::STLStringAppendUninitializedAmortized(dest, a.size());
+  STLStringAppendUninitializedAmortized(dest, a.size());
   char* const begin = &(*dest)[0];
   char* out = begin + old_size;
   out = Append(out, a);
@@ -289,8 +198,7 @@ void StrAppend(y_absl::Nonnull<TString*> dest, const AlphaNum& a,
   ASSERT_NO_OVERLAP(*dest, a);
   ASSERT_NO_OVERLAP(*dest, b);
   TString::size_type old_size = dest->size();
-  strings_internal::STLStringAppendUninitializedAmortized(dest,
-                                                          a.size() + b.size());
+  STLStringAppendUninitializedAmortized(dest, a.size() + b.size());
   char* const begin = &(*dest)[0];
   char* out = begin + old_size;
   out = Append(out, a);
@@ -304,8 +212,7 @@ void StrAppend(y_absl::Nonnull<TString*> dest, const AlphaNum& a,
   ASSERT_NO_OVERLAP(*dest, b);
   ASSERT_NO_OVERLAP(*dest, c);
   TString::size_type old_size = dest->size();
-  strings_internal::STLStringAppendUninitializedAmortized(
-      dest, a.size() + b.size() + c.size());
+  STLStringAppendUninitializedAmortized(dest, a.size() + b.size() + c.size());
   char* const begin = &(*dest)[0];
   char* out = begin + old_size;
   out = Append(out, a);
@@ -321,7 +228,7 @@ void StrAppend(y_absl::Nonnull<TString*> dest, const AlphaNum& a,
   ASSERT_NO_OVERLAP(*dest, c);
   ASSERT_NO_OVERLAP(*dest, d);
   TString::size_type old_size = dest->size();
-  strings_internal::STLStringAppendUninitializedAmortized(
+  STLStringAppendUninitializedAmortized(
       dest, a.size() + b.size() + c.size() + d.size());
   char* const begin = &(*dest)[0];
   char* out = begin + old_size;
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.h
index 67d117f104..cd48de1168 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_cat.h
@@ -93,6 +93,8 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <initializer_list>
+#include <limits>
 #include <util/generic/string.h>
 #include <type_traits>
 #include <utility>
@@ -312,6 +314,10 @@ class AlphaNum {
   // No bool ctor -- bools convert to an integral type.
   // A bool ctor would also convert incoming pointers (bletch).
 
+  // Prevent brace initialization
+  template <typename T>
+  AlphaNum(std::initializer_list<T>) = delete;  // NOLINT(runtime/explicit)
+
   AlphaNum(int x)  // NOLINT(runtime/explicit)
       : piece_(digits_, static_cast<size_t>(
                             numbers_internal::FastIntToBuffer(x, digits_) -
@@ -451,36 +457,77 @@ TString CatPieces(std::initializer_list<y_absl::string_view> pieces);
 void AppendPieces(y_absl::Nonnull<TString*> dest,
                   std::initializer_list<y_absl::string_view> pieces);
 
-void STLStringAppendUninitializedAmortized(TString* dest, size_t to_append);
+template <typename Integer>
+TString IntegerToString(Integer i) {
+  // Any integer (signed/unsigned) up to 64 bits can be formatted into a buffer
+  // with 22 bytes (including NULL at the end).
+  constexpr size_t kMaxDigits10 = 22;
+  TString result;
+  strings_internal::STLStringResizeUninitialized(&result, kMaxDigits10);
+  char* start = &result[0];
+  // note: this can be optimized to not write last zero.
+  char* end = numbers_internal::FastIntToBuffer(i, start);
+  auto size = static_cast<size_t>(end - start);
+  assert((size < result.size()) &&
+         "StrCat(Integer) does not fit into kMaxDigits10");
+  result.erase(size);
+  return result;
+}
+template <typename Float>
+TString FloatToString(Float f) {
+  TString result;
+  strings_internal::STLStringResizeUninitialized(
+      &result, numbers_internal::kSixDigitsToBufferSize);
+  char* start = &result[0];
+  result.erase(numbers_internal::SixDigitsToBuffer(f, start));
+  return result;
+}
 
 // `SingleArgStrCat` overloads take built-in `int`, `long` and `long long` types
 // (signed / unsigned) to avoid ambiguity on the call side. If we used int32_t
 // and int64_t, then at least one of the three (`int` / `long` / `long long`)
 // would have been ambiguous when passed to `SingleArgStrCat`.
-TString SingleArgStrCat(int x);
-TString SingleArgStrCat(unsigned int x);
-TString SingleArgStrCat(long x);                // NOLINT
-TString SingleArgStrCat(unsigned long x);       // NOLINT
-TString SingleArgStrCat(long long x);           // NOLINT
-TString SingleArgStrCat(unsigned long long x);  // NOLINT
-TString SingleArgStrCat(float x);
-TString SingleArgStrCat(double x);
-
-// `SingleArgStrAppend` overloads are defined here for the same reasons as with
-// `SingleArgStrCat` above.
-void SingleArgStrAppend(TString& str, int x);
-void SingleArgStrAppend(TString& str, unsigned int x);
-void SingleArgStrAppend(TString& str, long x);                // NOLINT
-void SingleArgStrAppend(TString& str, unsigned long x);       // NOLINT
-void SingleArgStrAppend(TString& str, long long x);           // NOLINT
-void SingleArgStrAppend(TString& str, unsigned long long x);  // NOLINT
-
-template <typename T,
-          typename = std::enable_if_t<std::is_arithmetic<T>::value &&
-                                      !std::is_same<T, char>::value &&
-                                      !std::is_same<T, bool>::value>>
+inline TString SingleArgStrCat(int x) { return IntegerToString(x); }
+inline TString SingleArgStrCat(unsigned int x) {
+  return IntegerToString(x);
+}
+// NOLINTNEXTLINE
+inline TString SingleArgStrCat(long x) { return IntegerToString(x); }
+// NOLINTNEXTLINE
+inline TString SingleArgStrCat(unsigned long x) {
+  return IntegerToString(x);
+}
+// NOLINTNEXTLINE
+inline TString SingleArgStrCat(long long x) { return IntegerToString(x); }
+// NOLINTNEXTLINE
+inline TString SingleArgStrCat(unsigned long long x) {
+  return IntegerToString(x);
+}
+inline TString SingleArgStrCat(float x) { return FloatToString(x); }
+inline TString SingleArgStrCat(double x) { return FloatToString(x); }
+
+// As of September 2023, the SingleArgStrCat() optimization is only enabled for
+// libc++. The reasons for this are:
+// 1) The SSO size for libc++ is 23, while libstdc++ and MSSTL have an SSO size
+// of 15. Since IntegerToString unconditionally resizes the string to 22 bytes,
+// this causes both libstdc++ and MSSTL to allocate.
+// 2) strings_internal::STLStringResizeUninitialized() only has an
+// implementation that avoids initialization when using libc++. This isn't as
+// relevant as (1), and the cost should be benchmarked if (1) ever changes on
+// libstc++ or MSSTL.
+#ifdef _LIBCPP_VERSION
+#define Y_ABSL_INTERNAL_STRCAT_ENABLE_FAST_CASE true
+#else
+#define Y_ABSL_INTERNAL_STRCAT_ENABLE_FAST_CASE false
+#endif
+
+template <typename T, typename = std::enable_if_t<
+                          Y_ABSL_INTERNAL_STRCAT_ENABLE_FAST_CASE &&
+                          std::is_arithmetic<T>{} && !std::is_same<T, char>{}>>
 using EnableIfFastCase = T;
 
+#undef Y_ABSL_INTERNAL_STRCAT_ENABLE_FAST_CASE
+
 }  // namespace strings_internal
 
 Y_ABSL_MUST_USE_RESULT inline TString StrCat() { return TString(); }
@@ -556,67 +603,6 @@ inline void StrAppend(y_absl::Nonnull<TString*> dest, const AlphaNum& a,
              static_cast<const AlphaNum&>(args).Piece()...});
 }
 
-template <class String, class T>
-std::enable_if_t<
-    std::is_integral<y_absl::strings_internal::EnableIfFastCase<T>>::value, void>
-StrAppend(y_absl::Nonnull<String*> result, T i) {
-  return y_absl::strings_internal::SingleArgStrAppend(*result, i);
-}
-
-// This overload is only selected if all the parameters are numbers that can be
-// handled quickly.
-// Later we can look into how we can extend this to more general argument
-// mixtures without bloating codegen too much, or copying unnecessarily.
-template <typename String, typename... T>
-std::enable_if_t<
-    (sizeof...(T) > 1),
-    std::common_type_t<std::conditional_t<
-        true, void, y_absl::strings_internal::EnableIfFastCase<T>>...>>
-StrAppend(y_absl::Nonnull<String*> str, T... args) {
-  // Do not add unnecessary variables, logic, or even "free" lambdas here.
-  // They can add overhead for the compiler and/or at run time.
-  // Furthermore, assume this function will be inlined.
-  // This function is carefully tailored to be able to be largely optimized away
-  // so that it becomes near-equivalent to the caller handling each argument
-  // individually while minimizing register pressure, so that the compiler
-  // can inline it with minimal overhead.
-
-  // First, calculate the total length, so we can perform just a single resize.
-  // Save all the lengths for later.
-  size_t total_length = 0;
-  const ptrdiff_t lengths[] = {
-      y_absl::numbers_internal::GetNumDigitsOrNegativeIfNegative(args)...};
-  for (const ptrdiff_t possibly_negative_length : lengths) {
-    // Lengths are negative for negative numbers. Keep them for later use, but
-    // take their absolute values for calculating total lengths;
-    total_length += possibly_negative_length < 0
-                        ? static_cast<size_t>(-possibly_negative_length)
-                        : static_cast<size_t>(possibly_negative_length);
-  }
-
-  // Now reserve space for all the arguments.
-  const size_t old_size = str->size();
-  y_absl::strings_internal::STLStringAppendUninitializedAmortized(str,
-                                                                total_length);
-
-  // Finally, output each argument one-by-one, from left to right.
-  size_t i = 0;  // The current argument we're processing
-  ptrdiff_t n;   // The length of the current argument
-  typename String::pointer pos = &(*str)[old_size];
-  using SomeTrivialEmptyType = std::false_type;
-  const SomeTrivialEmptyType dummy;
-  // Ugly code due to the lack of C++17 fold expressions
-  const SomeTrivialEmptyType dummies[] = {
-      (/* Comma expressions are poor man's C++17 fold expression for C++14 */
-       (void)(n = lengths[i]),
-       (void)(n < 0 ? (void)(*pos++ = '-'), (n = ~n) : 0),
-       (void)y_absl::numbers_internal::FastIntToBufferBackward(
-           y_absl::numbers_internal::UnsignedAbsoluteValue(std::move(args)),
-           pos += n, static_cast<uint32_t>(n)),
-       (void)++i, dummy)...};
-  (void)dummies;  // Remove & migrate to fold expressions in C++17
-}
-
 // Helper function for the future StrCat default floating-point format, %.6g
 // This is fast.
 inline strings_internal::AlphaNumBuffer<
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_format.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_format.h
index 63c6b4505f..c2f9d81d50 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_format.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_format.h
@@ -181,7 +181,7 @@ class FormatCountCapture {
 // For a `FormatSpec` to be valid at compile-time, it must be provided as
 // either:
 //
-// * A `constexpr` literal or `y_absl::string_view`, which is how it most often
+// * A `constexpr` literal or `y_absl::string_view`, which is how it is most often
 //   used.
 // * A `ParsedFormat` instantiation, which ensures the format string is
 //   valid before use. (See below.)
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_join.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_join.h
index 9fc0f37af5..23c51cf95c 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_join.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_join.h
@@ -247,12 +247,20 @@ TString StrJoin(const Range& range, y_absl::string_view separator,
   return strings_internal::JoinRange(range, separator, fmt);
 }
 
-template <typename T, typename Formatter>
+template <typename T, typename Formatter,
+          typename = typename std::enable_if<
+              !std::is_convertible<T, y_absl::string_view>::value>::type>
 TString StrJoin(std::initializer_list<T> il, y_absl::string_view separator,
                     Formatter&& fmt) {
   return strings_internal::JoinRange(il, separator, fmt);
 }
 
+template <typename Formatter>
+inline TString StrJoin(std::initializer_list<y_absl::string_view> il,
+                           y_absl::string_view separator, Formatter&& fmt) {
+  return strings_internal::JoinRange(il, separator, fmt);
+}
+
 template <typename... T, typename Formatter>
 TString StrJoin(const std::tuple<T...>& value, y_absl::string_view separator,
                     Formatter&& fmt) {
@@ -269,16 +277,22 @@ TString StrJoin(const Range& range, y_absl::string_view separator) {
   return strings_internal::JoinRange(range, separator);
 }
 
-template <typename T>
-TString StrJoin(std::initializer_list<T> il,
-                    y_absl::string_view separator) {
+template <typename T, typename = typename std::enable_if<!std::is_convertible<
+                          T, y_absl::string_view>::value>::type>
+TString StrJoin(std::initializer_list<T> il, y_absl::string_view separator) {
+  return strings_internal::JoinRange(il, separator);
+}
+
+inline TString StrJoin(std::initializer_list<y_absl::string_view> il,
+                           y_absl::string_view separator) {
   return strings_internal::JoinRange(il, separator);
 }
 
 template <typename... T>
 TString StrJoin(const std::tuple<T...>& value,
                     y_absl::string_view separator) {
-  return strings_internal::JoinAlgorithm(value, separator, AlphaNumFormatter());
+  return strings_internal::JoinTuple(value, separator,
+                                     std::index_sequence_for<T...>{});
 }
 
 Y_ABSL_NAMESPACE_END
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_split.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_split.h
index f75a1f18e9..1cb0f08cbf 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_split.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/str_split.h
@@ -456,7 +456,7 @@ using EnableSplitIfString =
 //   // Stores results in a std::set<TString>, which also performs
 //   // de-duplication and orders the elements in ascending order.
 //   std::set<TString> a = y_absl::StrSplit("b,a,c,a,b", ',');
-//   // v[0] == "a", v[1] == "b", v[2] = "c"
+//   // a[0] == "a", a[1] == "b", a[2] == "c"
 //
 //   // `StrSplit()` can be used within a range-based for loop, in which case
 //   // each element will be of type `y_absl::string_view`.
@@ -544,7 +544,7 @@ StrSplit(strings_internal::ConvertibleToStringView text, Delimiter d,
       typename strings_internal::SelectDelimiter<Delimiter>::type;
   return strings_internal::Splitter<DelimiterType, Predicate,
                                     y_absl::string_view>(
-      text.value(), DelimiterType(d), std::move(p));
+      text.value(), DelimiterType(std::move(d)), std::move(p));
 }
 
 template <typename Delimiter, typename Predicate, typename StringType,
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/string_view.h b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/string_view.h
index c3dcbacacf..551a2c87bf 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/string_view.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/string_view.h
@@ -159,7 +159,7 @@ Y_ABSL_NAMESPACE_BEGIN
 //
 //   y_absl::string_view() == y_absl::string_view("", 0)
 //   y_absl::string_view(nullptr, 0) == y_absl::string_view("abcdef"+6, 0)
-class string_view {
+class Y_ABSL_INTERNAL_ATTRIBUTE_VIEW string_view {
  public:
   using traits_type = std::char_traits<char>;
   using value_type = char;
@@ -173,6 +173,7 @@ class string_view {
   using reverse_iterator = const_reverse_iterator;
   using size_type = size_t;
   using difference_type = std::ptrdiff_t;
+  using absl_internal_is_view = std::true_type;
 
   static constexpr size_type npos = static_cast<size_type>(-1);
 
@@ -670,7 +671,7 @@ class string_view {
   }
 
   static constexpr size_type StrlenInternal(y_absl::Nonnull<const char*> str) {
-#if defined(_MSC_VER) && _MSC_VER >= 1910 && !defined(__clang__)
+#if defined(_MSC_VER) && !defined(__clang__)
     // MSVC 2017+ can evaluate this at compile-time.
     const char* begin = str;
     while (*str != '\0') ++str;
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/substitute.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/substitute.cc
index 72c9c71b2d..b64ce570f4 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/strings/substitute.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/strings/substitute.cc
@@ -18,6 +18,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <limits>
 #include <util/generic/string.h>
 
 #include "y_absl/base/config.h"
@@ -84,6 +85,9 @@ void SubstituteAndAppendArray(
 
   // Build the string.
   size_t original_size = output->size();
+  Y_ABSL_INTERNAL_CHECK(
+      size <= std::numeric_limits<size_t>::max() - original_size,
+      "size_t overflow");
   strings_internal::STLStringResizeUninitializedAmortized(output,
                                                           original_size + size);
   char* target = &(*output)[original_size];
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.cc
index 0053c1ed28..0f4fa5b7b5 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.cc
@@ -211,7 +211,7 @@ class NodeSet {
   Vec<int32_t> table_;
   uint32_t occupied_;     // Count of non-empty slots (includes deleted slots)
 
-  static uint32_t Hash(int32_t a) { return static_cast<uint32_t>(a * 41); }
+  static uint32_t Hash(int32_t a) { return static_cast<uint32_t>(a) * 41; }
 
   // Return index for storing v.  May return an empty index or deleted index
   uint32_t FindIndex(int32_t v) const {
@@ -333,7 +333,7 @@ class PointerMap {
 
  private:
   // Number of buckets in hash table for pointer lookups.
-  static constexpr uint32_t kHashTableSize = 8171;  // should be prime
+  static constexpr uint32_t kHashTableSize = 262139;  // should be prime
 
   const Vec<Node*>* nodes_;
   std::array<int32_t, kHashTableSize> table_;
@@ -365,6 +365,14 @@ static Node* FindNode(GraphCycles::Rep* rep, GraphId id) {
   return (n->version == NodeVersion(id)) ? n : nullptr;
 }
 
+void GraphCycles::TestOnlyAddNodes(uint32_t n) {
+  uint32_t old_size = rep_->nodes_.size();
+  rep_->nodes_.resize(n);
+  for (auto i = old_size; i < n; ++i) {
+    rep_->nodes_[i] = nullptr;
+  }
+}
+
 GraphCycles::GraphCycles() {
   InitArenaIfNecessary();
   rep_ = new (base_internal::LowLevelAlloc::AllocWithArena(sizeof(Rep), arena))
@@ -373,6 +381,7 @@ GraphCycles::GraphCycles() {
 
 GraphCycles::~GraphCycles() {
   for (auto* node : rep_->nodes_) {
+    if (node == nullptr) { continue; }
     node->Node::~Node();
     base_internal::LowLevelAlloc::Free(node);
   }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h
index ea39862db1..1dd7998734 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h
@@ -126,6 +126,11 @@ class GraphCycles {
   // Expensive: should only be called from graphcycles_test.cc.
   bool CheckInvariants() const;
 
+  // Test-only method to add more nodes. The nodes will not be valid, and this
+  // method should only be used to test the behavior of the graph when it is
+  // very full.
+  void TestOnlyAddNodes(uint32_t n);
+
   // ----------------------------------------------------
   struct Rep;
  private:
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/mutex.h b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/mutex.h
index 6dae8b408d..7dfefad6e6 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/mutex.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/mutex.h
@@ -148,7 +148,7 @@ struct SynchWaitParams;
 //
 // See also `MutexLock`, below, for scoped `Mutex` acquisition.
 
-class Y_ABSL_LOCKABLE Mutex {
+class Y_ABSL_LOCKABLE Y_ABSL_ATTRIBUTE_WARN_UNUSED Mutex {
  public:
   // Creates a `Mutex` that is not held by anyone. This constructor is
   // typically used for Mutexes allocated on the heap or the stack.
@@ -190,7 +190,7 @@ class Y_ABSL_LOCKABLE Mutex {
   // If the mutex can be acquired without blocking, does so exclusively and
   // returns `true`. Otherwise, returns `false`. Returns `true` with high
   // probability if the `Mutex` was free.
-  bool TryLock() Y_ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true);
+  Y_ABSL_MUST_USE_RESULT bool TryLock() Y_ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true);
 
   // Mutex::AssertHeld()
   //
@@ -255,7 +255,7 @@ class Y_ABSL_LOCKABLE Mutex {
   // If the mutex can be acquired without blocking, acquires this mutex for
   // shared access and returns `true`. Otherwise, returns `false`. Returns
   // `true` with high probability if the `Mutex` was free or shared.
-  bool ReaderTryLock() Y_ABSL_SHARED_TRYLOCK_FUNCTION(true);
+  Y_ABSL_MUST_USE_RESULT bool ReaderTryLock() Y_ABSL_SHARED_TRYLOCK_FUNCTION(true);
 
   // Mutex::AssertReaderHeld()
   //
@@ -281,7 +281,8 @@ class Y_ABSL_LOCKABLE Mutex {
 
   void WriterUnlock() Y_ABSL_UNLOCK_FUNCTION() { this->Unlock(); }
 
-  bool WriterTryLock() Y_ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
+  Y_ABSL_MUST_USE_RESULT bool WriterTryLock()
+      Y_ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
     return this->TryLock();
   }
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/civil_time.h b/contrib/restricted/abseil-cpp-tstring/y_absl/time/civil_time.h
index fcf4247360..a70939a023 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/civil_time.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/civil_time.h
@@ -55,7 +55,7 @@
 // Example:
 //
 //   // Construct a civil-time object for a specific day
-//   const y_absl::CivilDay cd(1969, 07, 20);
+//   const y_absl::CivilDay cd(1969, 7, 20);
 //
 //   // Construct a civil-time object for a specific second
 //   const y_absl::CivilSecond cd(2018, 8, 1, 12, 0, 1);
@@ -65,7 +65,7 @@
 // Example:
 //
 //   // Valid in C++14
-//   constexpr y_absl::CivilDay cd(1969, 07, 20);
+//   constexpr y_absl::CivilDay cd(1969, 7, 20);
 
 #ifndef Y_ABSL_TIME_CIVIL_TIME_H_
 #define Y_ABSL_TIME_CIVIL_TIME_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/clock.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/time/clock.cc
index 332b9978f9..b9f94d4355 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/clock.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/clock.cc
@@ -88,11 +88,25 @@ Y_ABSL_NAMESPACE_END
 namespace y_absl {
 Y_ABSL_NAMESPACE_BEGIN
 namespace time_internal {
+
+// On some processors, consecutive reads of the cycle counter may yield the
+// same value (weakly-increasing). In debug mode, clear the least significant
+// bits to discourage depending on a strictly-increasing Now() value.
+// In x86-64's debug mode, discourage depending on a strictly-increasing Now()
+// value.
+#if !defined(NDEBUG) && defined(__x86_64__)
+constexpr int64_t kCycleClockNowMask = ~int64_t{0xff};
+#else
+constexpr int64_t kCycleClockNowMask = ~int64_t{0};
+#endif
+
 // This is a friend wrapper around UnscaledCycleClock::Now()
 // (needed to access UnscaledCycleClock).
 class UnscaledCycleClockWrapperForGetCurrentTime {
  public:
-  static int64_t Now() { return base_internal::UnscaledCycleClock::Now(); }
+  static int64_t Now() {
+    return base_internal::UnscaledCycleClock::Now() & kCycleClockNowMask;
+  }
 };
 }  // namespace time_internal
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/duration.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/time/duration.cc
index 62c355ce80..da44b06d5b 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/duration.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/duration.cc
@@ -219,7 +219,7 @@ struct SafeMultiply {
                  ? static_cast<uint128>(Uint128Low64(a) * Uint128Low64(b))
                  : a * b;
     }
-    return b == 0 ? b : (a > kuint128max / b) ? kuint128max : a * b;
+    return b == 0 ? b : (a > Uint128Max() / b) ? Uint128Max() : a * b;
   }
 };
 
@@ -280,33 +280,35 @@ inline bool IDivFastPath(const Duration num, const Duration den, int64_t* q,
   int64_t den_hi = time_internal::GetRepHi(den);
   uint32_t den_lo = time_internal::GetRepLo(den);
 
-  if (den_hi == 0 && den_lo == kTicksPerNanosecond) {
-    // Dividing by 1ns
-    if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000000) {
-      *q = num_hi * 1000000000 + num_lo / kTicksPerNanosecond;
-      *rem = time_internal::MakeDuration(0, num_lo % den_lo);
-      return true;
-    }
-  } else if (den_hi == 0 && den_lo == 100 * kTicksPerNanosecond) {
-    // Dividing by 100ns (common when converting to Universal time)
-    if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 10000000) {
-      *q = num_hi * 10000000 + num_lo / (100 * kTicksPerNanosecond);
-      *rem = time_internal::MakeDuration(0, num_lo % den_lo);
-      return true;
-    }
-  } else if (den_hi == 0 && den_lo == 1000 * kTicksPerNanosecond) {
-    // Dividing by 1us
-    if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000) {
-      *q = num_hi * 1000000 + num_lo / (1000 * kTicksPerNanosecond);
-      *rem = time_internal::MakeDuration(0, num_lo % den_lo);
-      return true;
-    }
-  } else if (den_hi == 0 && den_lo == 1000000 * kTicksPerNanosecond) {
-    // Dividing by 1ms
-    if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000) {
-      *q = num_hi * 1000 + num_lo / (1000000 * kTicksPerNanosecond);
-      *rem = time_internal::MakeDuration(0, num_lo % den_lo);
-      return true;
+  if (den_hi == 0) {
+    if (den_lo == kTicksPerNanosecond) {
+      // Dividing by 1ns
+      if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000000) {
+        *q = num_hi * 1000000000 + num_lo / kTicksPerNanosecond;
+        *rem = time_internal::MakeDuration(0, num_lo % den_lo);
+        return true;
+      }
+    } else if (den_lo == 100 * kTicksPerNanosecond) {
+      // Dividing by 100ns (common when converting to Universal time)
+      if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 10000000) {
+        *q = num_hi * 10000000 + num_lo / (100 * kTicksPerNanosecond);
+        *rem = time_internal::MakeDuration(0, num_lo % den_lo);
+        return true;
+      }
+    } else if (den_lo == 1000 * kTicksPerNanosecond) {
+      // Dividing by 1us
+      if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000) {
+        *q = num_hi * 1000000 + num_lo / (1000 * kTicksPerNanosecond);
+        *rem = time_internal::MakeDuration(0, num_lo % den_lo);
+        return true;
+      }
+    } else if (den_lo == 1000000 * kTicksPerNanosecond) {
+      // Dividing by 1ms
+      if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000) {
+        *q = num_hi * 1000 + num_lo / (1000000 * kTicksPerNanosecond);
+        *rem = time_internal::MakeDuration(0, num_lo % den_lo);
+        return true;
+      }
     }
   } else if (den_hi > 0 && den_lo == 0) {
     // Dividing by positive multiple of 1s
@@ -342,19 +344,10 @@ inline bool IDivFastPath(const Duration num, const Duration den, int64_t* q,
 
 }  // namespace
 
-namespace time_internal {
+namespace {
 
-// The 'satq' argument indicates whether the quotient should saturate at the
-// bounds of int64_t.  If it does saturate, the difference will spill over to
-// the remainder.  If it does not saturate, the remainder remain accurate,
-// but the returned quotient will over/underflow int64_t and should not be used.
-int64_t IDivDuration(bool satq, const Duration num, const Duration den,
+int64_t IDivSlowPath(bool satq, const Duration num, const Duration den,
                      Duration* rem) {
-  int64_t q = 0;
-  if (IDivFastPath(num, den, &q, rem)) {
-    return q;
-  }
-
   const bool num_neg = num < ZeroDuration();
   const bool den_neg = den < ZeroDuration();
   const bool quotient_neg = num_neg != den_neg;
@@ -391,7 +384,27 @@ int64_t IDivDuration(bool satq, const Duration num, const Duration den,
   return -static_cast<int64_t>(Uint128Low64(quotient128 - 1) & kint64max) - 1;
 }
 
-}  // namespace time_internal
+// The 'satq' argument indicates whether the quotient should saturate at the
+// bounds of int64_t.  If it does saturate, the difference will spill over to
+// the remainder.  If it does not saturate, the remainder remain accurate,
+// but the returned quotient will over/underflow int64_t and should not be used.
+Y_ABSL_ATTRIBUTE_ALWAYS_INLINE inline int64_t IDivDurationImpl(bool satq,
+                                                             const Duration num,
+                                                             const Duration den,
+                                                             Duration* rem) {
+  int64_t q = 0;
+  if (IDivFastPath(num, den, &q, rem)) {
+    return q;
+  }
+  return IDivSlowPath(satq, num, den, rem);
+}
+
+}  // namespace
+
+int64_t IDivDuration(Duration num, Duration den, Duration* rem) {
+  return IDivDurationImpl(true, num, den,
+                          rem);  // trunc towards zero
+}
 
 //
 // Additive operators.
@@ -475,7 +488,7 @@ Duration& Duration::operator/=(double r) {
 }
 
 Duration& Duration::operator%=(Duration rhs) {
-  time_internal::IDivDuration(false, *this, rhs, this);
+  IDivDurationImpl(false, *this, rhs, this);
   return *this;
 }
 
@@ -501,9 +514,7 @@ double FDivDuration(Duration num, Duration den) {
 // Trunc/Floor/Ceil.
 //
 
-Duration Trunc(Duration d, Duration unit) {
-  return d - (d % unit);
-}
+Duration Trunc(Duration d, Duration unit) { return d - (d % unit); }
 
 Duration Floor(const Duration d, const Duration unit) {
   const y_absl::Duration td = Trunc(d, unit);
@@ -591,15 +602,9 @@ double ToDoubleMicroseconds(Duration d) {
 double ToDoubleMilliseconds(Duration d) {
   return FDivDuration(d, Milliseconds(1));
 }
-double ToDoubleSeconds(Duration d) {
-  return FDivDuration(d, Seconds(1));
-}
-double ToDoubleMinutes(Duration d) {
-  return FDivDuration(d, Minutes(1));
-}
-double ToDoubleHours(Duration d) {
-  return FDivDuration(d, Hours(1));
-}
+double ToDoubleSeconds(Duration d) { return FDivDuration(d, Seconds(1)); }
+double ToDoubleMinutes(Duration d) { return FDivDuration(d, Minutes(1)); }
+double ToDoubleHours(Duration d) { return FDivDuration(d, Hours(1)); }
 
 timespec ToTimespec(Duration d) {
   timespec ts;
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/format.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/time/format.cc
index fca2ff6043..eb9f995333 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/format.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/format.cc
@@ -16,6 +16,7 @@
 
 #include <cctype>
 #include <cstdint>
+#include <utility>
 
 #include "y_absl/strings/match.h"
 #include "y_absl/strings/string_view.h"
@@ -136,7 +137,7 @@ bool ParseTime(y_absl::string_view format, y_absl::string_view input,
   if (b) {
     *time = Join(parts);
   } else if (err != nullptr) {
-    *err = error;
+    *err = std::move(error);
   }
   return b;
 }
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_libc.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_libc.cc
index a38a4a092d..473be412e4 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_libc.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_libc.cc
@@ -12,7 +12,7 @@
 //   See the License for the specific language governing permissions and
 //   limitations under the License.
 
-#if defined(_WIN32) || defined(_WIN64)
+#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_WIN32)
 #define _CRT_SECURE_NO_WARNINGS 1
 #endif
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_lookup.cc b/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_lookup.cc
index dc495d0606..75797a1990 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_lookup.cc
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/time_zone_lookup.cc
@@ -17,9 +17,6 @@
 
 #if defined(__ANDROID__)
 #include <sys/system_properties.h>
-#if defined(__ANDROID_API__) && __ANDROID_API__ >= 21
-#include <dlfcn.h>
-#endif
 #endif
 
 #if defined(__APPLE__)
@@ -66,32 +63,6 @@ namespace time_internal {
 namespace cctz {
 
 namespace {
-#if defined(__ANDROID__) && defined(__ANDROID_API__) && __ANDROID_API__ >= 21
-// Android 'L' removes __system_property_get() from the NDK, however
-// it is still a hidden symbol in libc so we use dlsym() to access it.
-// See Chromium's base/sys_info_android.cc for a similar example.
-
-using property_get_func = int (*)(const char*, char*);
-
-property_get_func LoadSystemPropertyGet() {
-  int flag = RTLD_LAZY | RTLD_GLOBAL;
-#if defined(RTLD_NOLOAD)
-  flag |= RTLD_NOLOAD;  // libc.so should already be resident
-#endif
-  if (void* handle = dlopen("libc.so", flag)) {
-    void* sym = dlsym(handle, "__system_property_get");
-    dlclose(handle);
-    return reinterpret_cast<property_get_func>(sym);
-  }
-  return nullptr;
-}
-
-int __system_property_get(const char* name, char* value) {
-  static property_get_func system_property_get = LoadSystemPropertyGet();
-  return system_property_get ? system_property_get(name, value) : -1;
-}
-#endif
-
 #if defined(USE_WIN32_LOCAL_TIME_ZONE)
 // Calls the WinRT Calendar.GetTimeZone method to obtain the IANA ID of the
 // local time zone. Returns an empty vector in case of an error.
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/tzfile.h b/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/tzfile.h
index 114026d066..2be3bb8d98 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/tzfile.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/internal/cctz/src/tzfile.h
@@ -77,11 +77,11 @@ struct tzhead {
 ** time uses 8 rather than 4 chars,
 ** then a POSIX-TZ-environment-variable-style string for use in handling
 ** instants after the last transition time stored in the file
-** (with nothing between the newlines if there is no POSIX representation for
-** such instants).
+** (with nothing between the newlines if there is no POSIX.1-2017
+** representation for such instants).
 **
 ** If tz_version is '3' or greater, the above is extended as follows.
-** First, the POSIX TZ string's hour offset may range from -167
+** First, the TZ string's hour offset may range from -167
 ** through 167 as compared to the POSIX-required 0 through 24.
 ** Second, its DST start time may be January 1 at 00:00 and its stop
 ** time December 31 at 24:00 plus the difference between DST and
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/time/time.h b/contrib/restricted/abseil-cpp-tstring/y_absl/time/time.h
index 9d68396d5d..9b8079acfc 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/time/time.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/time/time.h
@@ -75,15 +75,22 @@
 struct timeval;
 #endif
 #include <chrono>  // NOLINT(build/c++11)
+
+#ifdef __cpp_lib_three_way_comparison
+#include <compare>
+#endif  // __cpp_lib_three_way_comparison
+
 #include <cmath>
 #include <cstdint>
 #include <ctime>
 #include <limits>
 #include <ostream>
+#include <ratio>  // NOLINT(build/c++11)
 #include <util/generic/string.h>
 #include <type_traits>
 #include <utility>
 
+#include "y_absl/base/attributes.h"
 #include "y_absl/base/config.h"
 #include "y_absl/base/macros.h"
 #include "y_absl/strings/string_view.h"
@@ -98,7 +105,6 @@ class Time;      // Defined below
 class TimeZone;  // Defined below
 
 namespace time_internal {
-int64_t IDivDuration(bool satq, Duration num, Duration den, Duration* rem);
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr Time FromUnixDuration(Duration d);
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr Duration ToUnixDuration(Time t);
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr int64_t GetRepHi(Duration d);
@@ -306,6 +312,14 @@ class Duration {
 };
 
 // Relational Operators
+
+#ifdef __cpp_lib_three_way_comparison
+
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr std::strong_ordering operator<=>(
+    Duration lhs, Duration rhs);
+
+#endif  // __cpp_lib_three_way_comparison
+
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr bool operator<(Duration lhs,
                                                        Duration rhs);
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr bool operator>(Duration lhs,
@@ -338,30 +352,6 @@ Y_ABSL_ATTRIBUTE_CONST_FUNCTION inline Duration operator-(Duration lhs,
   return lhs -= rhs;
 }
 
-// Multiplicative Operators
-// Integer operands must be representable as int64_t.
-template <typename T>
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION Duration operator*(Duration lhs, T rhs) {
-  return lhs *= rhs;
-}
-template <typename T>
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION Duration operator*(T lhs, Duration rhs) {
-  return rhs *= lhs;
-}
-template <typename T>
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION Duration operator/(Duration lhs, T rhs) {
-  return lhs /= rhs;
-}
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION inline int64_t operator/(Duration lhs,
-                                                       Duration rhs) {
-  return time_internal::IDivDuration(true, lhs, rhs,
-                                     &lhs);  // trunc towards zero
-}
-Y_ABSL_ATTRIBUTE_CONST_FUNCTION inline Duration operator%(Duration lhs,
-                                                        Duration rhs) {
-  return lhs %= rhs;
-}
-
 // IDivDuration()
 //
 // Divides a numerator `Duration` by a denominator `Duration`, returning the
@@ -390,10 +380,7 @@ Y_ABSL_ATTRIBUTE_CONST_FUNCTION inline Duration operator%(Duration lhs,
 //   // Here, q would overflow int64_t, so rem accounts for the difference.
 //   int64_t q = y_absl::IDivDuration(a, b, &rem);
 //   // q == std::numeric_limits<int64_t>::max(), rem == a - b * q
-inline int64_t IDivDuration(Duration num, Duration den, Duration* rem) {
-  return time_internal::IDivDuration(true, num, den,
-                                     rem);  // trunc towards zero
-}
+int64_t IDivDuration(Duration num, Duration den, Duration* rem);
 
 // FDivDuration()
 //
@@ -409,6 +396,30 @@ inline int64_t IDivDuration(Duration num, Duration den, Duration* rem) {
 //   // d == 1.5
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION double FDivDuration(Duration num, Duration den);
 
+// Multiplicative Operators
+// Integer operands must be representable as int64_t.
+template <typename T>
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION Duration operator*(Duration lhs, T rhs) {
+  return lhs *= rhs;
+}
+template <typename T>
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION Duration operator*(T lhs, Duration rhs) {
+  return rhs *= lhs;
+}
+template <typename T>
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION Duration operator/(Duration lhs, T rhs) {
+  return lhs /= rhs;
+}
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION inline int64_t operator/(Duration lhs,
+                                                       Duration rhs) {
+  return IDivDuration(lhs, rhs,
+                      &lhs);  // trunc towards zero
+}
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION inline Duration operator%(Duration lhs,
+                                                        Duration rhs) {
+  return lhs %= rhs;
+}
+
 // ZeroDuration()
 //
 // Returns a zero-length duration. This function behaves just like the default
@@ -841,6 +852,11 @@ class Time {
  private:
   friend constexpr Time time_internal::FromUnixDuration(Duration d);
   friend constexpr Duration time_internal::ToUnixDuration(Time t);
+
+#ifdef __cpp_lib_three_way_comparison
+  friend constexpr std::strong_ordering operator<=>(Time lhs, Time rhs);
+#endif  // __cpp_lib_three_way_comparison
+
   friend constexpr bool operator<(Time lhs, Time rhs);
   friend constexpr bool operator==(Time lhs, Time rhs);
   friend Duration operator-(Time lhs, Time rhs);
@@ -852,6 +868,15 @@ class Time {
 };
 
 // Relational Operators
+#ifdef __cpp_lib_three_way_comparison
+
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr std::strong_ordering operator<=>(
+    Time lhs, Time rhs) {
+  return lhs.rep_ <=> rhs.rep_;
+}
+
+#endif  // __cpp_lib_three_way_comparison
+
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr bool operator<(Time lhs, Time rhs) {
   return lhs.rep_ < rhs.rep_;
 }
@@ -1727,6 +1752,25 @@ Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr bool operator<(Duration lhs,
              : time_internal::GetRepLo(lhs) < time_internal::GetRepLo(rhs);
 }
 
+
+#ifdef __cpp_lib_three_way_comparison
+
+Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr std::strong_ordering operator<=>(
+    Duration lhs, Duration rhs) {
+  const int64_t lhs_hi = time_internal::GetRepHi(lhs);
+  const int64_t rhs_hi = time_internal::GetRepHi(rhs);
+  if (auto c = lhs_hi <=> rhs_hi; c != std::strong_ordering::equal) {
+    return c;
+  }
+  const uint32_t lhs_lo = time_internal::GetRepLo(lhs);
+  const uint32_t rhs_lo = time_internal::GetRepLo(rhs);
+  return (lhs_hi == (std::numeric_limits<int64_t>::min)())
+             ? (lhs_lo + 1) <=> (rhs_lo + 1)
+             : lhs_lo <=> rhs_lo;
+}
+
+#endif  // __cpp_lib_three_way_comparison
+
 Y_ABSL_ATTRIBUTE_CONST_FUNCTION constexpr bool operator==(Duration lhs,
                                                         Duration rhs) {
   return time_internal::GetRepHi(lhs) == time_internal::GetRepHi(rhs) &&
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/types/compare.h b/contrib/restricted/abseil-cpp-tstring/y_absl/types/compare.h
new file mode 100644
index 0000000000..4560e03e07
--- /dev/null
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/types/compare.h
@@ -0,0 +1,505 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// -----------------------------------------------------------------------------
+// compare.h
+// -----------------------------------------------------------------------------
+//
+// This header file defines the `y_absl::partial_ordering`, `y_absl::weak_ordering`,
+// and `y_absl::strong_ordering` types for storing the results of three way
+// comparisons.
+//
+// Example:
+//   y_absl::weak_ordering compare(const TString& a, const TString& b);
+//
+// These are C++11 compatible versions of the C++20 corresponding types
+// (`std::partial_ordering`, etc.) and are designed to be drop-in replacements
+// for code compliant with C++20.
+
+#ifndef Y_ABSL_TYPES_COMPARE_H_
+#define Y_ABSL_TYPES_COMPARE_H_
+
+#include "y_absl/base/config.h"
+
+#ifdef Y_ABSL_USES_STD_ORDERING
+
+#include <compare>  // IWYU pragma: export
+#include <type_traits>
+
+#include "y_absl/meta/type_traits.h"
+
+#else
+
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <type_traits>
+
+#include "y_absl/base/attributes.h"
+#include "y_absl/base/macros.h"
+#include "y_absl/meta/type_traits.h"
+
+#endif
+
+namespace y_absl {
+Y_ABSL_NAMESPACE_BEGIN
+
+#ifdef Y_ABSL_USES_STD_ORDERING
+
+using std::partial_ordering;
+using std::strong_ordering;
+using std::weak_ordering;
+
+#else
+
+namespace compare_internal {
+
+using value_type = int8_t;
+
+class OnlyLiteralZero {
+ public:
+#if Y_ABSL_HAVE_ATTRIBUTE(enable_if) && !defined(__CUDACC__)
+  // On clang, we can avoid triggering modernize-use-nullptr by only enabling
+  // this overload when the value is a compile time integer constant equal to 0.
+  //
+  // In c++20, this could be a static_assert in a consteval function.
+  constexpr OnlyLiteralZero(int n)  // NOLINT
+      __attribute__((enable_if(n == 0, "Only literal `0` is allowed."))) {}
+#else  // Y_ABSL_HAVE_ATTRIBUTE(enable_if)
+  // Accept only literal zero since it can be implicitly converted to a pointer
+  // to member type. nullptr constants will be caught by the other constructor
+  // which accepts a nullptr_t.
+  //
+  // This constructor is not used for clang since it triggers
+  // modernize-use-nullptr.
+  constexpr OnlyLiteralZero(int OnlyLiteralZero::*) noexcept {}  // NOLINT
+#endif
+
+  // Fails compilation when `nullptr` or integral type arguments other than
+  // `int` are passed. This constructor doesn't accept `int` because literal `0`
+  // has type `int`. Literal `0` arguments will be implicitly converted to
+  // `std::nullptr_t` and accepted by the above constructor, while other `int`
+  // arguments will fail to be converted and cause compilation failure.
+  template <typename T, typename = typename std::enable_if<
+                            std::is_same<T, std::nullptr_t>::value ||
+                            (std::is_integral<T>::value &&
+                             !std::is_same<T, int>::value)>::type>
+  OnlyLiteralZero(T) {  // NOLINT
+    static_assert(sizeof(T) < 0, "Only literal `0` is allowed.");
+  }
+};
+
+enum class eq : value_type {
+  equal = 0,
+  equivalent = equal,
+  nonequal = 1,
+  nonequivalent = nonequal,
+};
+
+enum class ord : value_type { less = -1, greater = 1 };
+
+enum class ncmp : value_type { unordered = -127 };
+
+// Define macros to allow for creation or emulation of C++17 inline variables
+// based on whether the feature is supported. Note: we can't use
+// Y_ABSL_INTERNAL_INLINE_CONSTEXPR here because the variables here are of
+// incomplete types so they need to be defined after the types are complete.
+#ifdef __cpp_inline_variables
+
+// A no-op expansion that can be followed by a semicolon at class level.
+#define Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(name) static_assert(true, "")
+
+#define Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(type, name) \
+  static const type name
+
+#define Y_ABSL_COMPARE_INLINE_INIT(type, name, init) \
+  inline constexpr type type::name(init)
+
+#else  // __cpp_inline_variables
+
+#define Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(name) \
+  Y_ABSL_CONST_INIT static const T name
+
+// A no-op expansion that can be followed by a semicolon at class level.
+#define Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(type, name) static_assert(true, "")
+
+#define Y_ABSL_COMPARE_INLINE_INIT(type, name, init) \
+  template <typename T>                            \
+  const T compare_internal::type##_base<T>::name(init)
+
+#endif  // __cpp_inline_variables
+
+// These template base classes allow for defining the values of the constants
+// in the header file (for performance) without using inline variables (which
+// aren't available in C++11).
+template <typename T>
+struct partial_ordering_base {
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(less);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(equivalent);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(greater);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(unordered);
+};
+
+template <typename T>
+struct weak_ordering_base {
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(less);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(equivalent);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(greater);
+};
+
+template <typename T>
+struct strong_ordering_base {
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(less);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(equal);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(equivalent);
+  Y_ABSL_COMPARE_INLINE_BASECLASS_DECL(greater);
+};
+
+}  // namespace compare_internal
+
+class partial_ordering
+    : public compare_internal::partial_ordering_base<partial_ordering> {
+  explicit constexpr partial_ordering(compare_internal::eq v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  explicit constexpr partial_ordering(compare_internal::ord v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  explicit constexpr partial_ordering(compare_internal::ncmp v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  friend struct compare_internal::partial_ordering_base<partial_ordering>;
+
+  constexpr bool is_ordered() const noexcept {
+    return value_ !=
+           compare_internal::value_type(compare_internal::ncmp::unordered);
+  }
+
+ public:
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, less);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, equivalent);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, greater);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, unordered);
+
+  // Comparisons
+  friend constexpr bool operator==(
+      partial_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.is_ordered() && v.value_ == 0;
+  }
+  friend constexpr bool operator!=(
+      partial_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return !v.is_ordered() || v.value_ != 0;
+  }
+  friend constexpr bool operator<(
+      partial_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.is_ordered() && v.value_ < 0;
+  }
+  friend constexpr bool operator<=(
+      partial_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.is_ordered() && v.value_ <= 0;
+  }
+  friend constexpr bool operator>(
+      partial_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.is_ordered() && v.value_ > 0;
+  }
+  friend constexpr bool operator>=(
+      partial_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.is_ordered() && v.value_ >= 0;
+  }
+  friend constexpr bool operator==(compare_internal::OnlyLiteralZero,
+                                   partial_ordering v) noexcept {
+    return v.is_ordered() && 0 == v.value_;
+  }
+  friend constexpr bool operator!=(compare_internal::OnlyLiteralZero,
+                                   partial_ordering v) noexcept {
+    return !v.is_ordered() || 0 != v.value_;
+  }
+  friend constexpr bool operator<(compare_internal::OnlyLiteralZero,
+                                  partial_ordering v) noexcept {
+    return v.is_ordered() && 0 < v.value_;
+  }
+  friend constexpr bool operator<=(compare_internal::OnlyLiteralZero,
+                                   partial_ordering v) noexcept {
+    return v.is_ordered() && 0 <= v.value_;
+  }
+  friend constexpr bool operator>(compare_internal::OnlyLiteralZero,
+                                  partial_ordering v) noexcept {
+    return v.is_ordered() && 0 > v.value_;
+  }
+  friend constexpr bool operator>=(compare_internal::OnlyLiteralZero,
+                                   partial_ordering v) noexcept {
+    return v.is_ordered() && 0 >= v.value_;
+  }
+  friend constexpr bool operator==(partial_ordering v1,
+                                   partial_ordering v2) noexcept {
+    return v1.value_ == v2.value_;
+  }
+  friend constexpr bool operator!=(partial_ordering v1,
+                                   partial_ordering v2) noexcept {
+    return v1.value_ != v2.value_;
+  }
+
+ private:
+  compare_internal::value_type value_;
+};
+Y_ABSL_COMPARE_INLINE_INIT(partial_ordering, less, compare_internal::ord::less);
+Y_ABSL_COMPARE_INLINE_INIT(partial_ordering, equivalent,
+                         compare_internal::eq::equivalent);
+Y_ABSL_COMPARE_INLINE_INIT(partial_ordering, greater,
+                         compare_internal::ord::greater);
+Y_ABSL_COMPARE_INLINE_INIT(partial_ordering, unordered,
+                         compare_internal::ncmp::unordered);
+
+class weak_ordering
+    : public compare_internal::weak_ordering_base<weak_ordering> {
+  explicit constexpr weak_ordering(compare_internal::eq v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  explicit constexpr weak_ordering(compare_internal::ord v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  friend struct compare_internal::weak_ordering_base<weak_ordering>;
+
+ public:
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(weak_ordering, less);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(weak_ordering, equivalent);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(weak_ordering, greater);
+
+  // Conversions
+  constexpr operator partial_ordering() const noexcept {  // NOLINT
+    return value_ == 0 ? partial_ordering::equivalent
+                       : (value_ < 0 ? partial_ordering::less
+                                     : partial_ordering::greater);
+  }
+  // Comparisons
+  friend constexpr bool operator==(
+      weak_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ == 0;
+  }
+  friend constexpr bool operator!=(
+      weak_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ != 0;
+  }
+  friend constexpr bool operator<(
+      weak_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ < 0;
+  }
+  friend constexpr bool operator<=(
+      weak_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ <= 0;
+  }
+  friend constexpr bool operator>(
+      weak_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ > 0;
+  }
+  friend constexpr bool operator>=(
+      weak_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ >= 0;
+  }
+  friend constexpr bool operator==(compare_internal::OnlyLiteralZero,
+                                   weak_ordering v) noexcept {
+    return 0 == v.value_;
+  }
+  friend constexpr bool operator!=(compare_internal::OnlyLiteralZero,
+                                   weak_ordering v) noexcept {
+    return 0 != v.value_;
+  }
+  friend constexpr bool operator<(compare_internal::OnlyLiteralZero,
+                                  weak_ordering v) noexcept {
+    return 0 < v.value_;
+  }
+  friend constexpr bool operator<=(compare_internal::OnlyLiteralZero,
+                                   weak_ordering v) noexcept {
+    return 0 <= v.value_;
+  }
+  friend constexpr bool operator>(compare_internal::OnlyLiteralZero,
+                                  weak_ordering v) noexcept {
+    return 0 > v.value_;
+  }
+  friend constexpr bool operator>=(compare_internal::OnlyLiteralZero,
+                                   weak_ordering v) noexcept {
+    return 0 >= v.value_;
+  }
+  friend constexpr bool operator==(weak_ordering v1,
+                                   weak_ordering v2) noexcept {
+    return v1.value_ == v2.value_;
+  }
+  friend constexpr bool operator!=(weak_ordering v1,
+                                   weak_ordering v2) noexcept {
+    return v1.value_ != v2.value_;
+  }
+
+ private:
+  compare_internal::value_type value_;
+};
+Y_ABSL_COMPARE_INLINE_INIT(weak_ordering, less, compare_internal::ord::less);
+Y_ABSL_COMPARE_INLINE_INIT(weak_ordering, equivalent,
+                         compare_internal::eq::equivalent);
+Y_ABSL_COMPARE_INLINE_INIT(weak_ordering, greater,
+                         compare_internal::ord::greater);
+
+class strong_ordering
+    : public compare_internal::strong_ordering_base<strong_ordering> {
+  explicit constexpr strong_ordering(compare_internal::eq v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  explicit constexpr strong_ordering(compare_internal::ord v) noexcept
+      : value_(static_cast<compare_internal::value_type>(v)) {}
+  friend struct compare_internal::strong_ordering_base<strong_ordering>;
+
+ public:
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, less);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, equal);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, equivalent);
+  Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, greater);
+
+  // Conversions
+  constexpr operator partial_ordering() const noexcept {  // NOLINT
+    return value_ == 0 ? partial_ordering::equivalent
+                       : (value_ < 0 ? partial_ordering::less
+                                     : partial_ordering::greater);
+  }
+  constexpr operator weak_ordering() const noexcept {  // NOLINT
+    return value_ == 0
+               ? weak_ordering::equivalent
+               : (value_ < 0 ? weak_ordering::less : weak_ordering::greater);
+  }
+  // Comparisons
+  friend constexpr bool operator==(
+      strong_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ == 0;
+  }
+  friend constexpr bool operator!=(
+      strong_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ != 0;
+  }
+  friend constexpr bool operator<(
+      strong_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ < 0;
+  }
+  friend constexpr bool operator<=(
+      strong_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ <= 0;
+  }
+  friend constexpr bool operator>(
+      strong_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ > 0;
+  }
+  friend constexpr bool operator>=(
+      strong_ordering v, compare_internal::OnlyLiteralZero) noexcept {
+    return v.value_ >= 0;
+  }
+  friend constexpr bool operator==(compare_internal::OnlyLiteralZero,
+                                   strong_ordering v) noexcept {
+    return 0 == v.value_;
+  }
+  friend constexpr bool operator!=(compare_internal::OnlyLiteralZero,
+                                   strong_ordering v) noexcept {
+    return 0 != v.value_;
+  }
+  friend constexpr bool operator<(compare_internal::OnlyLiteralZero,
+                                  strong_ordering v) noexcept {
+    return 0 < v.value_;
+  }
+  friend constexpr bool operator<=(compare_internal::OnlyLiteralZero,
+                                   strong_ordering v) noexcept {
+    return 0 <= v.value_;
+  }
+  friend constexpr bool operator>(compare_internal::OnlyLiteralZero,
+                                  strong_ordering v) noexcept {
+    return 0 > v.value_;
+  }
+  friend constexpr bool operator>=(compare_internal::OnlyLiteralZero,
+                                   strong_ordering v) noexcept {
+    return 0 >= v.value_;
+  }
+  friend constexpr bool operator==(strong_ordering v1,
+                                   strong_ordering v2) noexcept {
+    return v1.value_ == v2.value_;
+  }
+  friend constexpr bool operator!=(strong_ordering v1,
+                                   strong_ordering v2) noexcept {
+    return v1.value_ != v2.value_;
+  }
+
+ private:
+  compare_internal::value_type value_;
+};
+Y_ABSL_COMPARE_INLINE_INIT(strong_ordering, less, compare_internal::ord::less);
+Y_ABSL_COMPARE_INLINE_INIT(strong_ordering, equal, compare_internal::eq::equal);
+Y_ABSL_COMPARE_INLINE_INIT(strong_ordering, equivalent,
+                         compare_internal::eq::equivalent);
+Y_ABSL_COMPARE_INLINE_INIT(strong_ordering, greater,
+                         compare_internal::ord::greater);
+
+#undef Y_ABSL_COMPARE_INLINE_BASECLASS_DECL
+#undef Y_ABSL_COMPARE_INLINE_SUBCLASS_DECL
+#undef Y_ABSL_COMPARE_INLINE_INIT
+
+#endif  // Y_ABSL_USES_STD_ORDERING
+
+namespace compare_internal {
+// We also provide these comparator adapter functions for internal y_absl use.
+
+// Helper functions to do a boolean comparison of two keys given a boolean
+// or three-way comparator.
+// SFINAE prevents implicit conversions to bool (such as from int).
+template <typename BoolT,
+          y_absl::enable_if_t<std::is_same<bool, BoolT>::value, int> = 0>
+constexpr bool compare_result_as_less_than(const BoolT r) { return r; }
+constexpr bool compare_result_as_less_than(const y_absl::weak_ordering r) {
+  return r < 0;
+}
+
+template <typename Compare, typename K, typename LK>
+constexpr bool do_less_than_comparison(const Compare &compare, const K &x,
+                                       const LK &y) {
+  return compare_result_as_less_than(compare(x, y));
+}
+
+// Helper functions to do a three-way comparison of two keys given a boolean or
+// three-way comparator.
+// SFINAE prevents implicit conversions to int (such as from bool).
+template <typename Int,
+          y_absl::enable_if_t<std::is_same<int, Int>::value, int> = 0>
+constexpr y_absl::weak_ordering compare_result_as_ordering(const Int c) {
+  return c < 0 ? y_absl::weak_ordering::less
+               : c == 0 ? y_absl::weak_ordering::equivalent
+                        : y_absl::weak_ordering::greater;
+}
+constexpr y_absl::weak_ordering compare_result_as_ordering(
+    const y_absl::weak_ordering c) {
+  return c;
+}
+
+template <
+    typename Compare, typename K, typename LK,
+    y_absl::enable_if_t<!std::is_same<bool, y_absl::result_of_t<Compare(
+                                              const K &, const LK &)>>::value,
+                      int> = 0>
+constexpr y_absl::weak_ordering do_three_way_comparison(const Compare &compare,
+                                                      const K &x, const LK &y) {
+  return compare_result_as_ordering(compare(x, y));
+}
+template <
+    typename Compare, typename K, typename LK,
+    y_absl::enable_if_t<std::is_same<bool, y_absl::result_of_t<Compare(
+                                             const K &, const LK &)>>::value,
+                      int> = 0>
+constexpr y_absl::weak_ordering do_three_way_comparison(const Compare &compare,
+                                                      const K &x, const LK &y) {
+  return compare(x, y) ? y_absl::weak_ordering::less
+                       : compare(y, x) ? y_absl::weak_ordering::greater
+                                       : y_absl::weak_ordering::equivalent;
+}
+
+}  // namespace compare_internal
+Y_ABSL_NAMESPACE_END
+}  // namespace y_absl
+
+#endif  // Y_ABSL_TYPES_COMPARE_H_
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/optional.h b/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/optional.h
index faaf18711b..6c870a3aff 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/optional.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/optional.h
@@ -81,7 +81,7 @@ class optional_data_dtor_base {
 
   template <typename... Args>
   constexpr explicit optional_data_dtor_base(in_place_t, Args&&... args)
-      : engaged_(true), data_(y_absl::forward<Args>(args)...) {}
+      : engaged_(true), data_(std::forward<Args>(args)...) {}
 
   ~optional_data_dtor_base() { destruct(); }
 };
@@ -110,7 +110,7 @@ class optional_data_dtor_base<T, true> {
 
   template <typename... Args>
   constexpr explicit optional_data_dtor_base(in_place_t, Args&&... args)
-      : engaged_(true), data_(y_absl::forward<Args>(args)...) {}
+      : engaged_(true), data_(std::forward<Args>(args)...) {}
 };
 
 template <typename T>
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/variant.h b/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/variant.h
index da3bd41d86..eca59de50a 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/variant.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/types/internal/variant.h
@@ -26,6 +26,7 @@
 #include <stdexcept>
 #include <tuple>
 #include <type_traits>
+#include <utility>
 
 #include "y_absl/base/config.h"
 #include "y_absl/base/internal/identity.h"
@@ -214,7 +215,7 @@ constexpr ReturnType call_with_indices(FunctionObject&& function) {
       std::is_same<ReturnType, decltype(std::declval<FunctionObject>()(
                                    SizeT<Indices>()...))>::value,
       "Not all visitation overloads have the same return type.");
-  return y_absl::forward<FunctionObject>(function)(SizeT<Indices>()...);
+  return std::forward<FunctionObject>(function)(SizeT<Indices>()...);
 }
 
 template <class ReturnType, class FunctionObject, std::size_t... BoundIndices>
@@ -272,27 +273,14 @@ struct UnreachableSwitchCase {
   template <class Op>
   [[noreturn]] static VisitIndicesResultT<Op, std::size_t> Run(
       Op&& /*ignored*/) {
-#if Y_ABSL_HAVE_BUILTIN(__builtin_unreachable) || \
-    (defined(__GNUC__) && !defined(__clang__))
-    __builtin_unreachable();
-#elif defined(_MSC_VER)
-    __assume(false);
-#else
-    // Try to use assert of false being identified as an unreachable intrinsic.
-    // NOTE: We use assert directly to increase chances of exploiting an assume
-    //       intrinsic.
-    assert(false);  // NOLINT
-
-    // Hack to silence potential no return warning -- cause an infinite loop.
-    return Run(y_absl::forward<Op>(op));
-#endif  // Checks for __builtin_unreachable
+    Y_ABSL_UNREACHABLE();
   }
 };
 
 template <class Op, std::size_t I>
 struct ReachableSwitchCase {
   static VisitIndicesResultT<Op, std::size_t> Run(Op&& op) {
-    return y_absl::base_internal::invoke(y_absl::forward<Op>(op), SizeT<I>());
+    return y_absl::base_internal::invoke(std::forward<Op>(op), SizeT<I>());
   }
 };
 
@@ -357,74 +345,74 @@ struct VisitIndicesSwitch {
   static VisitIndicesResultT<Op, std::size_t> Run(Op&& op, std::size_t i) {
     switch (i) {
       case 0:
-        return PickCase<Op, 0, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 0, EndIndex>::Run(std::forward<Op>(op));
       case 1:
-        return PickCase<Op, 1, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 1, EndIndex>::Run(std::forward<Op>(op));
       case 2:
-        return PickCase<Op, 2, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 2, EndIndex>::Run(std::forward<Op>(op));
       case 3:
-        return PickCase<Op, 3, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 3, EndIndex>::Run(std::forward<Op>(op));
       case 4:
-        return PickCase<Op, 4, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 4, EndIndex>::Run(std::forward<Op>(op));
       case 5:
-        return PickCase<Op, 5, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 5, EndIndex>::Run(std::forward<Op>(op));
       case 6:
-        return PickCase<Op, 6, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 6, EndIndex>::Run(std::forward<Op>(op));
       case 7:
-        return PickCase<Op, 7, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 7, EndIndex>::Run(std::forward<Op>(op));
       case 8:
-        return PickCase<Op, 8, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 8, EndIndex>::Run(std::forward<Op>(op));
       case 9:
-        return PickCase<Op, 9, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 9, EndIndex>::Run(std::forward<Op>(op));
       case 10:
-        return PickCase<Op, 10, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 10, EndIndex>::Run(std::forward<Op>(op));
       case 11:
-        return PickCase<Op, 11, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 11, EndIndex>::Run(std::forward<Op>(op));
       case 12:
-        return PickCase<Op, 12, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 12, EndIndex>::Run(std::forward<Op>(op));
       case 13:
-        return PickCase<Op, 13, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 13, EndIndex>::Run(std::forward<Op>(op));
       case 14:
-        return PickCase<Op, 14, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 14, EndIndex>::Run(std::forward<Op>(op));
       case 15:
-        return PickCase<Op, 15, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 15, EndIndex>::Run(std::forward<Op>(op));
       case 16:
-        return PickCase<Op, 16, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 16, EndIndex>::Run(std::forward<Op>(op));
       case 17:
-        return PickCase<Op, 17, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 17, EndIndex>::Run(std::forward<Op>(op));
       case 18:
-        return PickCase<Op, 18, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 18, EndIndex>::Run(std::forward<Op>(op));
       case 19:
-        return PickCase<Op, 19, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 19, EndIndex>::Run(std::forward<Op>(op));
       case 20:
-        return PickCase<Op, 20, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 20, EndIndex>::Run(std::forward<Op>(op));
       case 21:
-        return PickCase<Op, 21, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 21, EndIndex>::Run(std::forward<Op>(op));
       case 22:
-        return PickCase<Op, 22, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 22, EndIndex>::Run(std::forward<Op>(op));
       case 23:
-        return PickCase<Op, 23, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 23, EndIndex>::Run(std::forward<Op>(op));
       case 24:
-        return PickCase<Op, 24, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 24, EndIndex>::Run(std::forward<Op>(op));
       case 25:
-        return PickCase<Op, 25, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 25, EndIndex>::Run(std::forward<Op>(op));
       case 26:
-        return PickCase<Op, 26, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 26, EndIndex>::Run(std::forward<Op>(op));
       case 27:
-        return PickCase<Op, 27, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 27, EndIndex>::Run(std::forward<Op>(op));
       case 28:
-        return PickCase<Op, 28, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 28, EndIndex>::Run(std::forward<Op>(op));
       case 29:
-        return PickCase<Op, 29, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 29, EndIndex>::Run(std::forward<Op>(op));
       case 30:
-        return PickCase<Op, 30, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 30, EndIndex>::Run(std::forward<Op>(op));
       case 31:
-        return PickCase<Op, 31, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 31, EndIndex>::Run(std::forward<Op>(op));
       case 32:
-        return PickCase<Op, 32, EndIndex>::Run(y_absl::forward<Op>(op));
+        return PickCase<Op, 32, EndIndex>::Run(std::forward<Op>(op));
       default:
         Y_ABSL_ASSERT(i == variant_npos);
-        return y_absl::base_internal::invoke(y_absl::forward<Op>(op), NPos());
+        return y_absl::base_internal::invoke(std::forward<Op>(op), NPos());
     }
   }
 };
@@ -437,7 +425,7 @@ struct VisitIndicesFallback {
         MakeVisitationMatrix<VisitIndicesResultT<Op, SizeT...>, Op,
                              index_sequence<(EndIndices + 1)...>,
                              index_sequence<>>::Run(),
-        (indices + 1)...)(y_absl::forward<Op>(op));
+        (indices + 1)...)(std::forward<Op>(op));
   }
 };
 
@@ -489,7 +477,7 @@ struct VisitIndicesVariadicImpl<y_absl::index_sequence<N...>, EndIndices...> {
     VisitIndicesResultT<Op, decltype(EndIndices)...> operator()(
         SizeT<I> /*index*/) && {
       return base_internal::invoke(
-          y_absl::forward<Op>(op),
+          std::forward<Op>(op),
           SizeT<UnflattenIndex<I, N, (EndIndices + 1)...>::value -
                 std::size_t{1}>()...);
     }
@@ -501,7 +489,7 @@ struct VisitIndicesVariadicImpl<y_absl::index_sequence<N...>, EndIndices...> {
   static VisitIndicesResultT<Op, decltype(EndIndices)...> Run(Op&& op,
                                                               SizeType... i) {
     return VisitIndicesSwitch<NumCasesOfSwitch<EndIndices...>::value>::Run(
-        FlattenedOp<Op>{y_absl::forward<Op>(op)},
+        FlattenedOp<Op>{std::forward<Op>(op)},
         FlattenIndices<(EndIndices + std::size_t{1})...>::Run(
             (i + std::size_t{1})...));
   }
@@ -612,7 +600,7 @@ struct VariantCoreAccess {
       TypedThrowBadVariantAccess<VariantAccessResult<I, Variant>>();
     }
 
-    return Access<I>(y_absl::forward<Variant>(self));
+    return Access<I>(std::forward<Variant>(self));
   }
 
   // The implementation of the move-assignment operation for a variant.
@@ -684,7 +672,7 @@ struct VariantCoreAccess {
 
     void operator()(SizeT<NewIndex::value> /*old_i*/
     ) const {
-      Access<NewIndex::value>(*left) = y_absl::forward<QualifiedNew>(other);
+      Access<NewIndex::value>(*left) = std::forward<QualifiedNew>(other);
     }
 
     template <std::size_t OldIndex>
@@ -695,13 +683,13 @@ struct VariantCoreAccess {
       if (std::is_nothrow_constructible<New, QualifiedNew>::value ||
           !std::is_nothrow_move_constructible<New>::value) {
         left->template emplace<NewIndex::value>(
-            y_absl::forward<QualifiedNew>(other));
+            std::forward<QualifiedNew>(other));
       } else {
         // the standard says "equivalent to
         // operator=(variant(std::forward<T>(t)))", but we use `emplace` here
         // because the variant's move assignment operator could be deleted.
         left->template emplace<NewIndex::value>(
-            New(y_absl::forward<QualifiedNew>(other)));
+            New(std::forward<QualifiedNew>(other)));
       }
     }
 
@@ -712,7 +700,7 @@ struct VariantCoreAccess {
   template <class Left, class QualifiedNew>
   static ConversionAssignVisitor<Left, QualifiedNew>
   MakeConversionAssignVisitor(Left* left, QualifiedNew&& qual) {
-    return {left, y_absl::forward<QualifiedNew>(qual)};
+    return {left, std::forward<QualifiedNew>(qual)};
   }
 
   // Backend for operations for `emplace()` which destructs `*self` then
@@ -723,7 +711,7 @@ struct VariantCoreAccess {
     Destroy(*self);
     using New = typename y_absl::variant_alternative<NewIndex, Self>::type;
     New* const result = ::new (static_cast<void*>(&self->state_))
-        New(y_absl::forward<Args>(args)...);
+        New(std::forward<Args>(args)...);
     self->index_ = NewIndex;
     return *result;
   }
@@ -919,9 +907,9 @@ struct PerformVisitation {
                                           Is, QualifiedVariants>...)>>::value,
         "All visitation overloads must have the same return type.");
     return y_absl::base_internal::invoke(
-        y_absl::forward<Op>(op),
+        std::forward<Op>(op),
         VariantCoreAccess::Access<Is>(
-            y_absl::forward<QualifiedVariants>(std::get<TupIs>(variant_tup)))...);
+            std::forward<QualifiedVariants>(std::get<TupIs>(variant_tup)))...);
   }
 
   template <std::size_t... TupIs, std::size_t... Is>
@@ -969,11 +957,11 @@ union Union<Head, Tail...> {
 
   template <class... P>
   explicit constexpr Union(EmplaceTag<0>, P&&... args)
-      : head(y_absl::forward<P>(args)...) {}
+      : head(std::forward<P>(args)...) {}
 
   template <std::size_t I, class... P>
   explicit constexpr Union(EmplaceTag<I>, P&&... args)
-      : tail(EmplaceTag<I - 1>{}, y_absl::forward<P>(args)...) {}
+      : tail(EmplaceTag<I - 1>{}, std::forward<P>(args)...) {}
 
   Head head;
   TailUnion tail;
@@ -1001,11 +989,11 @@ union DestructibleUnionImpl<Head, Tail...> {
 
   template <class... P>
   explicit constexpr DestructibleUnionImpl(EmplaceTag<0>, P&&... args)
-      : head(y_absl::forward<P>(args)...) {}
+      : head(std::forward<P>(args)...) {}
 
   template <std::size_t I, class... P>
   explicit constexpr DestructibleUnionImpl(EmplaceTag<I>, P&&... args)
-      : tail(EmplaceTag<I - 1>{}, y_absl::forward<P>(args)...) {}
+      : tail(EmplaceTag<I - 1>{}, std::forward<P>(args)...) {}
 
   ~DestructibleUnionImpl() {}
 
@@ -1036,7 +1024,7 @@ class VariantStateBase {
 
   template <std::size_t I, class... P>
   explicit constexpr VariantStateBase(EmplaceTag<I> tag, P&&... args)
-      : state_(tag, y_absl::forward<P>(args)...), index_(I) {}
+      : state_(tag, std::forward<P>(args)...), index_(I) {}
 
   explicit constexpr VariantStateBase(NoopConstructorTag)
       : state_(NoopConstructorTag()), index_(variant_npos) {}
@@ -1321,7 +1309,7 @@ class VariantMoveBaseNontrivial : protected VariantStateBaseDestructor<T...> {
       using Alternative =
           typename y_absl::variant_alternative<I, variant<T...>>::type;
       ::new (static_cast<void*>(&self->state_)) Alternative(
-          variant_internal::AccessUnion(y_absl::move(other->state_), i));
+          variant_internal::AccessUnion(std::move(other->state_), i));
     }
 
     void operator()(SizeT<y_absl::variant_npos> /*i*/) const {}
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/types/optional.h b/contrib/restricted/abseil-cpp-tstring/y_absl/types/optional.h
index fe5ff87fc7..aa06cf9ebb 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/types/optional.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/types/optional.h
@@ -151,7 +151,7 @@ class optional : private optional_internal::optional_data<T>,
                 std::is_same<InPlaceT, in_place_t>,
                 std::is_constructible<T, Args&&...> >::value>* = nullptr>
   constexpr explicit optional(InPlaceT, Args&&... args)
-      : data_base(in_place_t(), y_absl::forward<Args>(args)...) {}
+      : data_base(in_place_t(), std::forward<Args>(args)...) {}
 
   // Constructs a non-empty `optional` direct-initialized value of type `T` from
   // the arguments of an initializer_list and `std::forward<Args>(args)...`.
@@ -162,8 +162,7 @@ class optional : private optional_internal::optional_data<T>,
                 T, std::initializer_list<U>&, Args&&...>::value>::type>
   constexpr explicit optional(in_place_t, std::initializer_list<U> il,
                               Args&&... args)
-      : data_base(in_place_t(), il, y_absl::forward<Args>(args)...) {
-  }
+      : data_base(in_place_t(), il, std::forward<Args>(args)...) {}
 
   // Value constructor (implicit)
   template <
@@ -176,21 +175,21 @@ class optional : private optional_internal::optional_data<T>,
                             std::is_convertible<U&&, T>,
                             std::is_constructible<T, U&&> >::value,
           bool>::type = false>
-  constexpr optional(U&& v) : data_base(in_place_t(), y_absl::forward<U>(v)) {}
+  constexpr optional(U&& v) : data_base(in_place_t(), std::forward<U>(v)) {}
 
   // Value constructor (explicit)
   template <
       typename U = T,
       typename std::enable_if<
           y_absl::conjunction<y_absl::negation<std::is_same<
-                                in_place_t, typename std::decay<U>::type>>,
+                                in_place_t, typename std::decay<U>::type> >,
                             y_absl::negation<std::is_same<
-                                optional<T>, typename std::decay<U>::type>>,
-                            y_absl::negation<std::is_convertible<U&&, T>>,
-                            std::is_constructible<T, U&&>>::value,
+                                optional<T>, typename std::decay<U>::type> >,
+                            y_absl::negation<std::is_convertible<U&&, T> >,
+                            std::is_constructible<T, U&&> >::value,
           bool>::type = false>
   explicit constexpr optional(U&& v)
-      : data_base(in_place_t(), y_absl::forward<U>(v)) {}
+      : data_base(in_place_t(), std::forward<U>(v)) {}
 
   // Converting copy constructor (implicit)
   template <typename U,
@@ -437,7 +436,7 @@ class optional : private optional_internal::optional_data<T>,
     return reference();
   }
   constexpr const T&& operator*() const&& Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
-    return Y_ABSL_HARDENING_ASSERT(this->engaged_), y_absl::move(reference());
+    return Y_ABSL_HARDENING_ASSERT(this->engaged_), std::move(reference());
   }
   T&& operator*() && Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {
     Y_ABSL_HARDENING_ASSERT(this->engaged_);
@@ -492,7 +491,7 @@ class optional : private optional_internal::optional_data<T>,
   }
   constexpr const T&& value()
       const&& Y_ABSL_ATTRIBUTE_LIFETIME_BOUND {  // NOLINT(build/c++11)
-    return y_absl::move(
+    return std::move(
         static_cast<bool>(*this)
             ? reference()
             : (optional_internal::throw_bad_optional_access(), reference()));
@@ -511,9 +510,8 @@ class optional : private optional_internal::optional_data<T>,
                   "optional<T>::value_or: T must be copy constructible");
     static_assert(std::is_convertible<U&&, value_type>::value,
                   "optional<T>::value_or: U must be convertible to T");
-    return static_cast<bool>(*this)
-               ? **this
-               : static_cast<T>(y_absl::forward<U>(v));
+    return static_cast<bool>(*this) ? **this
+                                    : static_cast<T>(std::forward<U>(v));
   }
   template <typename U>
   T value_or(U&& v) && {  // NOLINT(build/c++11)
@@ -573,19 +571,18 @@ void swap(optional<T>& a, optional<T>& b) noexcept(noexcept(a.swap(b))) {
 //   static_assert(opt.value() == 1, "");
 template <typename T>
 constexpr optional<typename std::decay<T>::type> make_optional(T&& v) {
-  return optional<typename std::decay<T>::type>(y_absl::forward<T>(v));
+  return optional<typename std::decay<T>::type>(std::forward<T>(v));
 }
 
 template <typename T, typename... Args>
 constexpr optional<T> make_optional(Args&&... args) {
-  return optional<T>(in_place_t(), y_absl::forward<Args>(args)...);
+  return optional<T>(in_place_t(), std::forward<Args>(args)...);
 }
 
 template <typename T, typename U, typename... Args>
 constexpr optional<T> make_optional(std::initializer_list<U> il,
                                     Args&&... args) {
-  return optional<T>(in_place_t(), il,
-                     y_absl::forward<Args>(args)...);
+  return optional<T>(in_place_t(), il, std::forward<Args>(args)...);
 }
 
 // Relational operators [optional.relops]
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/types/span.h b/contrib/restricted/abseil-cpp-tstring/y_absl/types/span.h
index 83bee533f1..e6f1bdaee9 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/types/span.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/types/span.h
@@ -43,7 +43,7 @@
 //    * A read-only `y_absl::Span<const T>` can be implicitly constructed from an
 //      initializer list.
 //    * `y_absl::Span` has no `bytes()`, `size_bytes()`, `as_bytes()`, or
-//      `as_mutable_bytes()` methods
+//      `as_writable_bytes()` methods
 //    * `y_absl::Span` has no static extent template parameter, nor constructors
 //      which exist only because of the static extent parameter.
 //    * `y_absl::Span` has an explicit mutable-reference constructor
@@ -151,7 +151,7 @@ Y_ABSL_NAMESPACE_BEGIN
 //   int* my_array = new int[10];
 //   MyRoutine(y_absl::Span<const int>(my_array, 10));
 template <typename T>
-class Span {
+class Y_ABSL_INTERNAL_ATTRIBUTE_VIEW Span {
  private:
   // Used to determine whether a Span can be constructed from a container of
   // type C.
@@ -185,6 +185,7 @@ class Span {
   using const_reverse_iterator = std::reverse_iterator<const_iterator>;
   using size_type = size_t;
   using difference_type = ptrdiff_t;
+  using absl_internal_is_view = std::true_type;
 
   static const size_type npos = ~(size_type(0));
 
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/types/variant.h b/contrib/restricted/abseil-cpp-tstring/y_absl/types/variant.h
index dd21ab9e97..1ed8dfce00 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/types/variant.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/types/variant.h
@@ -303,11 +303,10 @@ constexpr T& get(variant<Types...>& v) {  // NOLINT
 }
 
 // Overload for getting a variant's rvalue by type.
-// Note: `y_absl::move()` is required to allow use of constexpr in C++11.
 template <class T, class... Types>
 constexpr T&& get(variant<Types...>&& v) {
   return variant_internal::VariantCoreAccess::CheckedAccess<
-      variant_internal::IndexOf<T, Types...>::value>(y_absl::move(v));
+      variant_internal::IndexOf<T, Types...>::value>(std::move(v));
 }
 
 // Overload for getting a variant's const lvalue by type.
@@ -318,11 +317,10 @@ constexpr const T& get(const variant<Types...>& v) {
 }
 
 // Overload for getting a variant's const rvalue by type.
-// Note: `y_absl::move()` is required to allow use of constexpr in C++11.
 template <class T, class... Types>
 constexpr const T&& get(const variant<Types...>&& v) {
   return variant_internal::VariantCoreAccess::CheckedAccess<
-      variant_internal::IndexOf<T, Types...>::value>(y_absl::move(v));
+      variant_internal::IndexOf<T, Types...>::value>(std::move(v));
 }
 
 // Overload for getting a variant's lvalue by index.
@@ -333,11 +331,10 @@ constexpr variant_alternative_t<I, variant<Types...>>& get(
 }
 
 // Overload for getting a variant's rvalue by index.
-// Note: `y_absl::move()` is required to allow use of constexpr in C++11.
 template <std::size_t I, class... Types>
 constexpr variant_alternative_t<I, variant<Types...>>&& get(
     variant<Types...>&& v) {
-  return variant_internal::VariantCoreAccess::CheckedAccess<I>(y_absl::move(v));
+  return variant_internal::VariantCoreAccess::CheckedAccess<I>(std::move(v));
 }
 
 // Overload for getting a variant's const lvalue by index.
@@ -348,11 +345,10 @@ constexpr const variant_alternative_t<I, variant<Types...>>& get(
 }
 
 // Overload for getting a variant's const rvalue by index.
-// Note: `y_absl::move()` is required to allow use of constexpr in C++11.
 template <std::size_t I, class... Types>
 constexpr const variant_alternative_t<I, variant<Types...>>&& get(
     const variant<Types...>&& v) {
-  return variant_internal::VariantCoreAccess::CheckedAccess<I>(y_absl::move(v));
+  return variant_internal::VariantCoreAccess::CheckedAccess<I>(std::move(v));
 }
 
 // get_if()
@@ -432,8 +428,8 @@ variant_internal::VisitResult<Visitor, Variants...> visit(Visitor&& vis,
   return variant_internal::
       VisitIndices<variant_size<y_absl::decay_t<Variants> >::value...>::Run(
           variant_internal::PerformVisitation<Visitor, Variants...>{
-              std::forward_as_tuple(y_absl::forward<Variants>(vars)...),
-              y_absl::forward<Visitor>(vis)},
+              std::forward_as_tuple(std::forward<Variants>(vars)...),
+              std::forward<Visitor>(vis)},
           vars.index()...);
 }
 
@@ -504,13 +500,12 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
       class T,
       std::size_t I = std::enable_if<
           variant_internal::IsNeitherSelfNorInPlace<variant,
-                                                    y_absl::decay_t<T>>::value,
-          variant_internal::IndexOfConstructedType<variant, T>>::type::value,
+                                                    y_absl::decay_t<T> >::value,
+          variant_internal::IndexOfConstructedType<variant, T> >::type::value,
       class Tj = y_absl::variant_alternative_t<I, variant>,
-      y_absl::enable_if_t<std::is_constructible<Tj, T>::value>* =
-          nullptr>
+      y_absl::enable_if_t<std::is_constructible<Tj, T>::value>* = nullptr>
   constexpr variant(T&& t) noexcept(std::is_nothrow_constructible<Tj, T>::value)
-      : Base(variant_internal::EmplaceTag<I>(), y_absl::forward<T>(t)) {}
+      : Base(variant_internal::EmplaceTag<I>(), std::forward<T>(t)) {}
 
   // Constructs a variant of an alternative type from the arguments through
   // direct-initialization.
@@ -524,7 +519,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
   constexpr explicit variant(in_place_type_t<T>, Args&&... args)
       : Base(variant_internal::EmplaceTag<
                  variant_internal::UnambiguousIndexOf<variant, T>::value>(),
-             y_absl::forward<Args>(args)...) {}
+             std::forward<Args>(args)...) {}
 
   // Constructs a variant of an alternative type from an initializer list
   // and other arguments through direct-initialization.
@@ -539,7 +534,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
                              Args&&... args)
       : Base(variant_internal::EmplaceTag<
                  variant_internal::UnambiguousIndexOf<variant, T>::value>(),
-             il, y_absl::forward<Args>(args)...) {}
+             il, std::forward<Args>(args)...) {}
 
   // Constructs a variant of an alternative type from a provided index,
   // through value-initialization using the provided forwarded arguments.
@@ -548,7 +543,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
                 variant_internal::VariantAlternativeSfinaeT<I, variant>,
                 Args...>::value>::type* = nullptr>
   constexpr explicit variant(in_place_index_t<I>, Args&&... args)
-      : Base(variant_internal::EmplaceTag<I>(), y_absl::forward<Args>(args)...) {}
+      : Base(variant_internal::EmplaceTag<I>(), std::forward<Args>(args)...) {}
 
   // Constructs a variant of an alternative type from a provided index,
   // through value-initialization of an initializer list and the provided
@@ -560,7 +555,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
   constexpr explicit variant(in_place_index_t<I>, std::initializer_list<U> il,
                              Args&&... args)
       : Base(variant_internal::EmplaceTag<I>(), il,
-             y_absl::forward<Args>(args)...) {}
+             std::forward<Args>(args)...) {}
 
   // Destructors
 
@@ -595,7 +590,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
           std::is_nothrow_constructible<Tj, T>::value) {
     variant_internal::VisitIndices<sizeof...(Tn) + 1>::Run(
         variant_internal::VariantCoreAccess::MakeConversionAssignVisitor(
-            this, y_absl::forward<T>(t)),
+            this, std::forward<T>(t)),
         index());
 
     return *this;
@@ -623,7 +618,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
   T& emplace(Args&&... args) {
     return variant_internal::VariantCoreAccess::Replace<
         variant_internal::UnambiguousIndexOf<variant, T>::value>(
-        this, y_absl::forward<Args>(args)...);
+        this, std::forward<Args>(args)...);
   }
 
   // Constructs a value of the given alternative type T within the variant using
@@ -644,7 +639,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
   T& emplace(std::initializer_list<U> il, Args&&... args) {
     return variant_internal::VariantCoreAccess::Replace<
         variant_internal::UnambiguousIndexOf<variant, T>::value>(
-        this, il, y_absl::forward<Args>(args)...);
+        this, il, std::forward<Args>(args)...);
   }
 
   // Destroys the current value of the variant (provided that
@@ -663,7 +658,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
                                       Args...>::value>::type* = nullptr>
   y_absl::variant_alternative_t<I, variant>& emplace(Args&&... args) {
     return variant_internal::VariantCoreAccess::Replace<I>(
-        this, y_absl::forward<Args>(args)...);
+        this, std::forward<Args>(args)...);
   }
 
   // Destroys the current value of the variant (provided that
@@ -681,7 +676,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
   y_absl::variant_alternative_t<I, variant>& emplace(std::initializer_list<U> il,
                                                    Args&&... args) {
     return variant_internal::VariantCoreAccess::Replace<I>(
-        this, il, y_absl::forward<Args>(args)...);
+        this, il, std::forward<Args>(args)...);
   }
 
   // variant::valueless_by_exception()
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/utility/utility.h b/contrib/restricted/abseil-cpp-tstring/y_absl/utility/utility.h
index f0c4db7f60..992763fd20 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/utility/utility.h
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/utility/utility.h
@@ -51,11 +51,14 @@ Y_ABSL_NAMESPACE_BEGIN
 // abstractions for platforms that had not yet provided them. Those
 // platforms are no longer supported. New code should simply use the
 // the ones from std directly.
+using std::exchange;
+using std::forward;
 using std::index_sequence;
 using std::index_sequence_for;
 using std::integer_sequence;
 using std::make_index_sequence;
 using std::make_integer_sequence;
+using std::move;
 
 namespace utility_internal {
 
@@ -129,27 +132,6 @@ template <size_t I>
 void in_place_index(utility_internal::InPlaceIndexTag<I>) {}
 #endif  // Y_ABSL_USES_STD_VARIANT
 
-// Constexpr move and forward
-
-// move()
-//
-// A constexpr version of `std::move()`, designed to be a drop-in replacement
-// for C++14's `std::move()`.
-template <typename T>
-constexpr y_absl::remove_reference_t<T>&& move(T&& t) noexcept {
-  return static_cast<y_absl::remove_reference_t<T>&&>(t);
-}
-
-// forward()
-//
-// A constexpr version of `std::forward()`, designed to be a drop-in replacement
-// for C++14's `std::forward()`.
-template <typename T>
-constexpr T&& forward(
-    y_absl::remove_reference_t<T>& t) noexcept {  // NOLINT(runtime/references)
-  return static_cast<T&&>(t);
-}
-
 namespace utility_internal {
 // Helper method for expanding tuple into a called method.
 template <typename Functor, typename Tuple, std::size_t... Indexes>
@@ -215,26 +197,6 @@ auto apply(Functor&& functor, Tuple&& t)
           typename std::remove_reference<Tuple>::type>::value>{});
 }
 
-// exchange
-//
-// Replaces the value of `obj` with `new_value` and returns the old value of
-// `obj`.  `y_absl::exchange` is designed to be a drop-in replacement for C++14's
-// `std::exchange`.
-//
-// Example:
-//
-//   Foo& operator=(Foo&& other) {
-//     ptr1_ = y_absl::exchange(other.ptr1_, nullptr);
-//     int1_ = y_absl::exchange(other.int1_, -1);
-//     return *this;
-//   }
-template <typename T, typename U = T>
-T exchange(T& obj, U&& new_value) {
-  T old_value = y_absl::move(obj);
-  obj = y_absl::forward<U>(new_value);
-  return old_value;
-}
-
 namespace utility_internal {
 template <typename T, typename Tuple, size_t... I>
 T make_from_tuple_impl(Tuple&& tup, y_absl::index_sequence<I...>) {
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/utility/ya.make b/contrib/restricted/abseil-cpp-tstring/y_absl/utility/ya.make
index ac5695f072..467248d279 100644
--- a/contrib/restricted/abseil-cpp-tstring/y_absl/utility/ya.make
+++ b/contrib/restricted/abseil-cpp-tstring/y_absl/utility/ya.make
@@ -6,9 +6,9 @@ LICENSE(Apache-2.0)
 
 LICENSE_TEXTS(.yandex_meta/licenses.list.txt)
 
-VERSION(20240116.2)
+VERSION(20240722.0)
 
-ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240116.2.tar.gz)
+ORIGINAL_SOURCE(https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz)
 
 NO_RUNTIME()