Update libc++ to b6d87773 (14 Jan 2022).

Notable changes:
* implement operator << for filesystem::directory_entry
* add std::ranges::in_in_result
* add std::ranges::owning_view
* add std::ranges::cdata
* add std::ranges::construct_at and destroy{,_n,_at}
* small fixes in std::ranges::data
* SFINAE away std::ranges::cbegin(const T&&) for non-borrowed T
* use arc4random to implement std::random_device on Apple
* introduce __fits_in_sso to put constexpr check into a central place
* introduce __debug_db_insert_c to put #if and constexpr check into a central place

ref:b3dd06bd52f06e8939227ca0f0a5873d0c211e48

12 files changed, 164 insertions, 43 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/access.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/access.h
index 246f8b20ca..0b9470fa40 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/access.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/access.h
@@ -163,11 +163,12 @@ namespace ranges {
 namespace __cbegin {
   struct __fn {
     template <class _Tp>
+      requires is_lvalue_reference_v<_Tp&&>
     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
-    constexpr auto operator()(_Tp& __t) const
-      noexcept(noexcept(ranges::begin(static_cast<const _Tp&>(__t))))
-      -> decltype(      ranges::begin(static_cast<const _Tp&>(__t)))
-      { return          ranges::begin(static_cast<const _Tp&>(__t)); }
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(ranges::begin(static_cast<const remove_reference_t<_Tp>&>(__t))))
+      -> decltype(      ranges::begin(static_cast<const remove_reference_t<_Tp>&>(__t)))
+      { return          ranges::begin(static_cast<const remove_reference_t<_Tp>&>(__t)); }
 
     template <class _Tp>
       requires is_rvalue_reference_v<_Tp&&>
@@ -190,11 +191,12 @@ namespace ranges {
 namespace __cend {
   struct __fn {
     template <class _Tp>
+      requires is_lvalue_reference_v<_Tp&&>
     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
-    constexpr auto operator()(_Tp& __t) const
-      noexcept(noexcept(ranges::end(static_cast<const _Tp&>(__t))))
-      -> decltype(      ranges::end(static_cast<const _Tp&>(__t)))
-      { return          ranges::end(static_cast<const _Tp&>(__t)); }
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(ranges::end(static_cast<const remove_reference_t<_Tp>&>(__t))))
+      -> decltype(      ranges::end(static_cast<const remove_reference_t<_Tp>&>(__t)))
+      { return          ranges::end(static_cast<const remove_reference_t<_Tp>&>(__t)); }
 
     template <class _Tp>
       requires is_rvalue_reference_v<_Tp&&>
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/all.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/all.h
index ccc77258ba..90327da814 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/all.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/all.h
@@ -14,9 +14,9 @@
 #include <__iterator/iterator_traits.h>
 #include <__ranges/access.h>
 #include <__ranges/concepts.h>
+#include <__ranges/owning_view.h>
 #include <__ranges/range_adaptor.h>
 #include <__ranges/ref_view.h>
-#include <__ranges/subrange.h>
 #include <__utility/auto_cast.h>
 #include <__utility/declval.h>
 #include <__utility/forward.h>
@@ -56,12 +56,12 @@ namespace __all {
     template<class _Tp>
       requires (!ranges::view<decay_t<_Tp>> &&
                 !requires (_Tp&& __t) { ranges::ref_view{_VSTD::forward<_Tp>(__t)}; } &&
-                 requires (_Tp&& __t) { ranges::subrange{_VSTD::forward<_Tp>(__t)}; })
+                 requires (_Tp&& __t) { ranges::owning_view{_VSTD::forward<_Tp>(__t)}; })
     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
     constexpr auto operator()(_Tp&& __t) const
-      noexcept(noexcept(ranges::subrange{_VSTD::forward<_Tp>(__t)}))
+      noexcept(noexcept(ranges::owning_view{_VSTD::forward<_Tp>(__t)}))
     {
-      return ranges::subrange{_VSTD::forward<_Tp>(__t)};
+      return ranges::owning_view{_VSTD::forward<_Tp>(__t)};
     }
   };
 }
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/concepts.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/concepts.h
index bad23c8c4b..fa31074ab6 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/concepts.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/concepts.h
@@ -9,6 +9,9 @@
 #ifndef _LIBCPP___RANGES_CONCEPTS_H
 #define _LIBCPP___RANGES_CONCEPTS_H
 
+#include <__concepts/constructible.h>
+#include <__concepts/movable.h>
+#include <__concepts/same_as.h>
 #include <__config>
 #include <__iterator/concepts.h>
 #include <__iterator/incrementable_traits.h>
@@ -20,7 +23,7 @@
 #include <__ranges/enable_borrowed_range.h>
 #include <__ranges/enable_view.h>
 #include <__ranges/size.h>
-#include <concepts>
+#include <initializer_list>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -114,12 +117,20 @@ namespace ranges {
   template <class _Tp>
   concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>;
 
-  template<class _Tp>
+  template <class _Tp>
+  inline constexpr bool __is_std_initializer_list = false;
+
+  template <class _Ep>
+  inline constexpr bool __is_std_initializer_list<initializer_list<_Ep>> = true;
+
+  template <class _Tp>
   concept viewable_range =
-    range<_Tp> && (
-      (view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) ||
-      (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>)
-    );
+    range<_Tp> &&
+    ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) ||
+     (!view<remove_cvref_t<_Tp>> &&
+      (is_lvalue_reference_v<_Tp> ||
+       (movable<remove_reference_t<_Tp>> && !__is_std_initializer_list<remove_cvref_t<_Tp>>))));
+
 } // namespace ranges
 
 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/copyable_box.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/copyable_box.h
index 4811690ada..c32596f17c 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/copyable_box.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/copyable_box.h
@@ -41,7 +41,7 @@ namespace ranges {
   // Primary template - uses std::optional and introduces an empty state in case assignment fails.
   template<__copy_constructible_object _Tp>
   class __copyable_box {
-    [[no_unique_address]] optional<_Tp> __val_;
+    _LIBCPP_NO_UNIQUE_ADDRESS optional<_Tp> __val_;
 
   public:
     template<class ..._Args>
@@ -116,7 +116,7 @@ namespace ranges {
   template<__copy_constructible_object _Tp>
     requires __doesnt_need_empty_state_for_copy<_Tp> && __doesnt_need_empty_state_for_move<_Tp>
   class __copyable_box<_Tp> {
-    [[no_unique_address]] _Tp __val_;
+    _LIBCPP_NO_UNIQUE_ADDRESS _Tp __val_;
 
   public:
     template<class ..._Args>
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/data.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/data.h
index cc151c59f3..69dfd479c0 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/data.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/data.h
@@ -9,13 +9,13 @@
 #ifndef _LIBCPP___RANGES_DATA_H
 #define _LIBCPP___RANGES_DATA_H
 
+#include <__concepts/class_or_enum.h>
 #include <__config>
 #include <__iterator/concepts.h>
 #include <__iterator/iterator_traits.h>
 #include <__memory/pointer_traits.h>
 #include <__ranges/access.h>
-#include <__utility/forward.h>
-#include <concepts>
+#include <__utility/auto_cast.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -35,34 +35,33 @@ namespace __data {
 
   template <class _Tp>
   concept __member_data =
+    __can_borrow<_Tp> &&
+    __workaround_52970<_Tp> &&
     requires(_Tp&& __t) {
-      { _VSTD::forward<_Tp>(__t) } -> __can_borrow;
-      { __t.data() } -> __ptr_to_object;
+      { _LIBCPP_AUTO_CAST(__t.data()) } -> __ptr_to_object;
     };
 
   template <class _Tp>
   concept __ranges_begin_invocable =
     !__member_data<_Tp> &&
+    __can_borrow<_Tp> &&
     requires(_Tp&& __t) {
-      { _VSTD::forward<_Tp>(__t) } -> __can_borrow;
-      { ranges::begin(_VSTD::forward<_Tp>(__t)) } -> contiguous_iterator;
+      { ranges::begin(__t) } -> contiguous_iterator;
     };
 
   struct __fn {
     template <__member_data _Tp>
-      requires __can_borrow<_Tp>
     _LIBCPP_HIDE_FROM_ABI
-    constexpr __ptr_to_object auto operator()(_Tp&& __t) const
+    constexpr auto operator()(_Tp&& __t) const
         noexcept(noexcept(__t.data())) {
       return __t.data();
     }
 
     template<__ranges_begin_invocable _Tp>
-      requires __can_borrow<_Tp>
     _LIBCPP_HIDE_FROM_ABI
-    constexpr __ptr_to_object auto operator()(_Tp&& __t) const
-        noexcept(noexcept(_VSTD::to_address(ranges::begin(_VSTD::forward<_Tp>(__t))))) {
-      return _VSTD::to_address(ranges::begin(_VSTD::forward<_Tp>(__t)));
+    constexpr auto operator()(_Tp&& __t) const
+        noexcept(noexcept(_VSTD::to_address(ranges::begin(__t)))) {
+      return _VSTD::to_address(ranges::begin(__t));
     }
   };
 }
@@ -72,6 +71,34 @@ inline namespace __cpo {
 } // namespace __cpo
 } // namespace ranges
 
+// [range.prim.cdata]
+
+namespace ranges {
+namespace __cdata {
+  struct __fn {
+    template <class _Tp>
+      requires is_lvalue_reference_v<_Tp&&>
+    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(ranges::data(static_cast<const remove_reference_t<_Tp>&>(__t))))
+      -> decltype(      ranges::data(static_cast<const remove_reference_t<_Tp>&>(__t)))
+      { return          ranges::data(static_cast<const remove_reference_t<_Tp>&>(__t)); }
+
+    template <class _Tp>
+      requires is_rvalue_reference_v<_Tp&&>
+    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(ranges::data(static_cast<const _Tp&&>(__t))))
+      -> decltype(      ranges::data(static_cast<const _Tp&&>(__t)))
+      { return          ranges::data(static_cast<const _Tp&&>(__t)); }
+  };
+}
+
+inline namespace __cpo {
+  inline constexpr auto cdata = __cdata::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/drop_view.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/drop_view.h
index 6adb09cf67..8d1ac87c93 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/drop_view.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/drop_view.h
@@ -45,7 +45,7 @@ namespace ranges {
     // one can't call begin() on it more than once.
     static constexpr bool _UseCache = forward_range<_View> && !(random_access_range<_View> && sized_range<_View>);
     using _Cache = _If<_UseCache, __non_propagating_cache<iterator_t<_View>>, __empty_cache>;
-    [[no_unique_address]] _Cache __cached_begin_ = _Cache();
+    _LIBCPP_NO_UNIQUE_ADDRESS _Cache __cached_begin_ = _Cache();
     range_difference_t<_View> __count_ = 0;
     _View __base_ = _View();
 
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/join_view.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/join_view.h
index 9aa69da76c..8dbafc7bd9 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/join_view.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/join_view.h
@@ -67,7 +67,7 @@ namespace ranges {
 
     static constexpr bool _UseCache = !is_reference_v<_InnerRange>;
     using _Cache = _If<_UseCache, __non_propagating_cache<remove_cvref_t<_InnerRange>>, __empty_cache>;
-    [[no_unique_address]] _Cache __cache_;
+    _LIBCPP_NO_UNIQUE_ADDRESS _Cache __cache_;
     _View __base_ = _View(); // TODO: [[no_unique_address]] makes clang crash! File a bug :)
 
   public:
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/owning_view.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/owning_view.h
new file mode 100644
index 0000000000..29182d2d8e
--- /dev/null
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/owning_view.h
@@ -0,0 +1,81 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#ifndef _LIBCPP___RANGES_OWNING_VIEW_H
+#define _LIBCPP___RANGES_OWNING_VIEW_H
+
+#include <__concepts/constructible.h>
+#include <__concepts/movable.h>
+#include <__config>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/data.h>
+#include <__ranges/empty.h>
+#include <__ranges/enable_borrowed_range.h>
+#include <__ranges/size.h>
+#include <__ranges/view_interface.h>
+#include <__utility/move.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if !defined(_LIBCPP_HAS_NO_RANGES)
+
+namespace ranges {
+  template<range _Rp>
+    requires movable<_Rp> && (!__is_std_initializer_list<remove_cvref_t<_Rp>>)
+  class owning_view : public view_interface<owning_view<_Rp>> {
+    _Rp __r_ = _Rp();
+
+public:
+    owning_view() requires default_initializable<_Rp> = default;
+    _LIBCPP_HIDE_FROM_ABI constexpr owning_view(_Rp&& __r) : __r_(_VSTD::move(__r)) {}
+
+    owning_view(owning_view&&) = default;
+    owning_view& operator=(owning_view&&) = default;
+
+    _LIBCPP_HIDE_FROM_ABI constexpr _Rp& base() & noexcept { return __r_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr const _Rp& base() const& noexcept { return __r_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr _Rp&& base() && noexcept { return _VSTD::move(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr const _Rp&& base() const&& noexcept { return _VSTD::move(__r_); }
+
+    _LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_Rp> begin() { return ranges::begin(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Rp> end() { return ranges::end(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr auto begin() const requires range<const _Rp> { return ranges::begin(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr auto end() const requires range<const _Rp> { return ranges::end(__r_); }
+
+    _LIBCPP_HIDE_FROM_ABI constexpr bool empty() requires requires { ranges::empty(__r_); }
+      { return ranges::empty(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const requires requires { ranges::empty(__r_); }
+      { return ranges::empty(__r_); }
+
+    _LIBCPP_HIDE_FROM_ABI constexpr auto size() requires sized_range<_Rp>
+      { return ranges::size(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr auto size() const requires sized_range<const _Rp>
+      { return ranges::size(__r_); }
+
+    _LIBCPP_HIDE_FROM_ABI constexpr auto data() requires contiguous_range<_Rp>
+      { return ranges::data(__r_); }
+    _LIBCPP_HIDE_FROM_ABI constexpr auto data() const requires contiguous_range<const _Rp>
+      { return ranges::data(__r_); }
+  };
+
+  template<class _Tp>
+  inline constexpr bool enable_borrowed_range<owning_view<_Tp>> = enable_borrowed_range<_Tp>;
+
+} // namespace ranges
+
+#endif // !defined(_LIBCPP_HAS_NO_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___RANGES_OWNING_VIEW_H
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/reverse_view.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/reverse_view.h
index 618be80457..f46df52259 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/reverse_view.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/reverse_view.h
@@ -43,8 +43,8 @@ namespace ranges {
     // amortized O(1) begin() method.
     static constexpr bool _UseCache = !random_access_range<_View> && !common_range<_View>;
     using _Cache = _If<_UseCache, __non_propagating_cache<reverse_iterator<iterator_t<_View>>>, __empty_cache>;
-    [[no_unique_address]] _Cache __cached_begin_ = _Cache();
-    [[no_unique_address]] _View __base_ = _View();
+    _LIBCPP_NO_UNIQUE_ADDRESS _Cache __cached_begin_ = _Cache();
+    _LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();
 
   public:
     _LIBCPP_HIDE_FROM_ABI
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/subrange.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/subrange.h
index 8e984f2bf0..76adbffef6 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/subrange.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/subrange.h
@@ -80,9 +80,9 @@ namespace ranges {
     static constexpr bool _MustProvideSizeAtConstruction = !_StoreSize; // just to improve compiler diagnostics
     struct _Empty { constexpr _Empty(auto) noexcept { } };
     using _Size = conditional_t<_StoreSize, make_unsigned_t<iter_difference_t<_Iter>>, _Empty>;
-    [[no_unique_address]] _Iter __begin_ = _Iter();
-    [[no_unique_address]] _Sent __end_ = _Sent();
-    [[no_unique_address]] _Size __size_ = 0;
+    _LIBCPP_NO_UNIQUE_ADDRESS _Iter __begin_ = _Iter();
+    _LIBCPP_NO_UNIQUE_ADDRESS _Sent __end_ = _Sent();
+    _LIBCPP_NO_UNIQUE_ADDRESS _Size __size_ = 0;
 
   public:
     _LIBCPP_HIDE_FROM_ABI
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/take_view.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/take_view.h
index 73a57fe96c..b1d6ab2afa 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/take_view.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/take_view.h
@@ -39,7 +39,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace ranges {
   template<view _View>
   class take_view : public view_interface<take_view<_View>> {
-    [[no_unique_address]] _View __base_ = _View();
+    _LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();
     range_difference_t<_View> __count_ = 0;
 
     template<bool> class __sentinel;
@@ -136,7 +136,7 @@ namespace ranges {
     using _Base = __maybe_const<_Const, _View>;
     template<bool _OtherConst>
     using _Iter = counted_iterator<iterator_t<__maybe_const<_OtherConst, _View>>>;
-    [[no_unique_address]] sentinel_t<_Base> __end_ = sentinel_t<_Base>();
+    _LIBCPP_NO_UNIQUE_ADDRESS sentinel_t<_Base> __end_ = sentinel_t<_Base>();
 
     template<bool>
     friend class take_view<_View>::__sentinel;
diff --git a/contrib/libs/cxxsupp/libcxx/include/__ranges/transform_view.h b/contrib/libs/cxxsupp/libcxx/include/__ranges/transform_view.h
index 0f53fbaa7e..020f51af8c 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__ranges/transform_view.h
+++ b/contrib/libs/cxxsupp/libcxx/include/__ranges/transform_view.h
@@ -62,8 +62,8 @@ class transform_view : public view_interface<transform_view<_View, _Fn>> {
   template<bool> class __iterator;
   template<bool> class __sentinel;
 
-  [[no_unique_address]] __copyable_box<_Fn> __func_;
-  [[no_unique_address]] _View __base_ = _View();
+  _LIBCPP_NO_UNIQUE_ADDRESS __copyable_box<_Fn> __func_;
+  _LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();
 
 public:
   _LIBCPP_HIDE_FROM_ABI