--- a/y_absl/flags/parse.cc
+++ b/y_absl/flags/parse.cc
@@ -147,6 +147,6 @@ bool ArgsList::ReadFromFlagfile(const TString& flag_file_name) {
   args_.emplace_back("");
 
-  TString line;
+  std::string line;
   bool success = true;
 
   while (std::getline(flag_file, line)) {
--- a/y_absl/numeric/int128.cc
+++ b/y_absl/numeric/int128.cc
@@ -220,1 +220,1 @@ TString Uint128ToFormattedString(uint128 v, std::ios_base::fmtflags flags) {
-  return os.str();
+  return TString(os.str());
--- a/y_absl/strings/ascii.h
+++ b/y_absl/strings/ascii.h
@@ -200,1 +200,1 @@ ABSL_MUST_USE_RESULT inline y_absl::string_view StripLeadingAsciiWhitespace(
-  auto it = std::find_if_not(str->begin(), str->end(), y_absl::ascii_isspace);
+  auto it = std::find_if_not(str->cbegin(), str->cend(), y_absl::ascii_isspace);
--- a/y_absl/strings/internal/str_format/arg.h
+++ b/y_absl/strings/internal/str_format/arg.h
@@ -24,5 +24,6 @@
 #include <memory>
 #include <sstream>
 #include <util/generic/string.h>
+#include <util/stream/str.h>
 #include <type_traits>
 #include <utility>
@@ -238,10 +239,11 @@ template <typename T>
 StringConvertResult FormatConvertImpl(const StreamedWrapper<T>& v,
                                       FormatConversionSpecImpl conv,
                                       FormatSinkImpl* out) {
-  std::ostringstream oss;
+  TString buf;
+  TStringOutput oss(buf);
   oss << v.v_;
-  if (!oss) return {false};
-  return str_format_internal::FormatConvertImpl(oss.str(), conv, out);
+  if (!buf) return {false};
+  return str_format_internal::FormatConvertImpl(buf, conv, out);
 }

 // Use templates and dependent types to delay evaluation of the function
--- a/y_absl/strings/internal/charconv_bigint.cc
+++ b/y_absl/strings/internal/charconv_bigint.cc
@@ -346,7 +346,7 @@ TString BigUnsigned<max_words>::ToString() const {
   if (result.empty()) {
     result.push_back('0');
   }
-  std::reverse(result.begin(), result.end());
+  std::reverse(result.begin(), result.vend());
   return result;
 }
 
--- a/y_absl/strings/cord.cc
+++ b/y_absl/strings/cord.cc
@@ -1895 +1895 @@ static TString ReportError(CordRep* root, CordRep* node) {
-  return buf.str();
+  return TString(buf.str());
--- a/y_absl/strings/str_cat.h
+++ b/y_absl/strings/str_cat.h
@@ -253,6 +253,9 @@ class AlphaNum {
       const std::basic_string<char, std::char_traits<char>, Allocator>& str)
       : piece_(str) {}

+  AlphaNum(const TString& str)
+      : piece_(str.data(), str.size()) {}
+
   // Use string literals ":" instead of character literals ':'.
   AlphaNum(char c) = delete;  // NOLINT(runtime/explicit)

--- a/y_absl/strings/substitute.h
+++ b/y_absl/strings/substitute.h
@@ -110,6 +110,8 @@ class Arg {
       : piece_(value) {}
   Arg(y_absl::string_view value)  // NOLINT(google-explicit-constructor)
       : piece_(value) {}
+  Arg(const TString& s)
+      : piece_(s.data(), s.size()) {}
 
   // Overloads for primitives
   //
--- a/y_absl/time/internal/cctz/src/time_zone_info.cc
+++ b/y_absl/time/internal/cctz/src/time_zone_info.cc
@@ -300,7 +300,7 @@ bool TimeZoneInfo::GetTransitionType(std::int_fast32_t utc_offset, bool is_dst,
   std::size_t abbr_index = abbreviations_.size();
   for (; type_index != transition_types_.size(); ++type_index) {
     const TransitionType& tt(transition_types_[type_index]);
-    const char* tt_abbr = &abbreviations_[tt.abbr_index];
+    const char* tt_abbr = &*abbreviations_.begin() + tt.abbr_index;
     if (tt_abbr == abbr) abbr_index = tt.abbr_index;
     if (tt.utc_offset == utc_offset && tt.is_dst == is_dst) {
       if (abbr_index == tt.abbr_index) break;  // reuse
@@ -736,1 +736,1 @@ time_zone::absolute_lookup TimeZoneInfo::LocalTime(
-          tt.is_dst, &abbreviations_[tt.abbr_index]};
+          tt.is_dst, &*abbreviations_.begin() + tt.abbr_index};
@@ -746,1 +746,1 @@ time_zone::absolute_lookup TimeZoneInfo::LocalTime(
-          tt.utc_offset, tt.is_dst, &abbreviations_[tt.abbr_index]};
+          tt.utc_offset, tt.is_dst, &*abbreviations_.begin() + tt.abbr_index};
@@ -888,7 +888,7 @@ TString TimeZoneInfo::Description() const {
   oss << "#trans=" << transitions_.size();
   oss << " #types=" << transition_types_.size();
   oss << " spec='" << future_spec_ << "'";
-  return oss.str();
+  return oss.str().c_str();
 }
 
 bool TimeZoneInfo::NextTransition(const time_point<seconds>& tp,
--- a/y_absl/time/internal/cctz/src/time_zone_info.cc	(index)
+++ b/y_absl/time/internal/cctz/src/time_zone_info.cc	(working tree)
@@ -754,7 +754,7 @@ std::unique_ptr<ZoneInfoSource> FuchsiaZoneInfoSource::Open(
     auto fp = FOpen(path.c_str(), "rb");
     if (fp == nullptr) continue;
 
-    TString version;
+    std::string version;
     if (!prefix.empty()) {
       // Fuchsia builds place the version in "<prefix>revision.txt".
       std::ifstream version_stream(prefix + "revision.txt");