From PR 134330

Apply initial _LIBCPP_CONSTEXPR_SINCE_CXX26

Add feature test macro

one test to start with

start seeing constexpr failures for at.pass.cpp

 member call on object outside its lifetime is not allowed in a constant expression

Move past member call on object past it's lifetime

Add ctor to initialize __value_type and __tree_node_base, and the object of unique_ptr

construction works, at() fails due to throw_out_of_range

can't intentionally throw in constexpr

note: cast from 'void *' is not allowed in a constant expression because the pointed object type 'std::__tree_node<std::__value_type<int, double>, min_pointer<void>>' is not similar to the target type 'std::__tree_node_base<min_pointer<void>>'

note: cast from 'void *' is not allowed in a constant expression because the pointed object type 'std::__tree_node<std::__value_type<int, double>, min_pointer<void>>' is not similar to the target type 'std::__tree_node_base<min_pointer<void>>

ignore min_allocator tests for now

at.pass.cpp works in cpp26 for some reason

empty.verify.cpp passes

index_key_.pass.cpp constexpr fixed, but other failure

index_rv_key.pass.cpp constexpr fixed, but other failure

fix index_tuple.pass.cpp

fix: iterator.pass.cpp

fix max_size.pass.cpp

size.pass.cpp

alloc.pass.cpp

blocked on assign_initializer_list

compare.pass.cpp

Modify all tests to have TEST_CONSTEXPR_CXX26 and without

passing at: copy_assign.addressof.compile.pass.cpp

failing at copy_assign.pass.cpp only in constexpr

pass deduct.pass.cpp

fix map.cons/from_range.pass.cpp

fail at map.cons/move_alloc.pass.cpp

fail at map.cons/move_assign.pass.cpp

fix map.cons/move_noexcept.pass.cpp

pass map.erasure/erase_if.pass.cpp

 error: call to deleted constructor at map.modifiers/emplace.pass.cpp

pass map.modifiers/erase_iter.pass.cpp

pass map.modifiers/extract_iterator.pass.cpp

TODO: node-handle tests

pass map.modifiers/extract_key.pass.cpp

pass map.modifiers/insert_and_emplace_allocator_requirements.pass.cpp

pass map.modifiers/insert_cv.pass.cpp

pass map.modifiers/insert_iter_cv.pass.cpp

pass map.modifiers/insert_iter_rv.pass.cpp

pass map.modifiers/insert_node_type.pass

pass map.modifiers/insert_node_type_hint.pass.cpp

pass map.modifiers/insert_or_assign.pass.cpp

pass map.modifiers/insert_rv.pass.cpp

pass map.modifiers/try.emplace.pass.cpp, fix typos

pass map.nonmember/compare.three_way.pass.cpp

pass map.nonmember/op_compare.pass.cpp

pass map.observers/key_comp.pass.cpp

pass map.observers/value_comp.pass.cpp

pass map.ops/contains.pass.cpp

pass map.ops/contains_transparent.pass.cpp

pass map.ops/count.pass.cpp

pass map.ops/count_transparent.pass.cpp

pass map.ops/equal_range_transparent.pass.cpp

pass map.special/member_swap.pass.cpp

pass map.value_compare/invoke.pass.cpp

pass map.value_compare/types.pass.cpp

cleanup

Pass compare.pass.cpp

pass incomplete_type.pass.cpp

error: call to deleted constructor of '__node_value_type' (aka 'std::__value_type<int, int>')

clang-format

Generate macro version correctly

fix unrelated CI failures

pass map.modifiers/emplace.pass.cpp

pass map.modifiers/emplace_hint.pass.cpp

at.pass.cpp passes again

iterator.pass.cpp passes

move_assign.pass.cpp constexpr fixed

move_alloc.pass.cpp constexpr fixed, other remains

copy_assign.pass.cpp constexpr fixed, other remains

erase_iter.pass.cpp

fix typo

map.ops pass

Partially fix assign_initializer_list.pass.cpp

Fix assign_initializer_list.pass.cpp

fix placement new to use std::addressof

fix copy_assign.pass.cpp

move alloc failure location

git-clang-format upstream/main

featuer test generation

<__type_traits/is_constant_evaluated.h>

__node_value_type

Use __libcpp_is_constant_evaluated, still at 7 failures

fix feature gen?

feature macros

? lang support

cf

restore pair to main

back at 7 failures due to min_allocator.h

cf?

insert_range.pass.cpp, empty passes, stuck at next

min_allocator to main

tree

clang format

fix CI?

try CI fix?

readability-identifier-naming

libcpp-hide-from-abi

cf

_Args not Args

map?

generic-cxx03

libcpp-hide-from-abi

cxx03

tmp

WIP???

constexpr test ID*

at.pass.cpp works

empty.pass.cpp

index_key.pass.cpp -> static_assert

error: static assertion failed due to requirement 'std::is_same<std::__tree_node<std::__value_type<CopyInsertable<1>, CopyInsertable<2>>, void *>, std::pair<const CopyInsertable<1>, CopyInsertable<2>>>::value': Only allowed to construct Up

iterator.pass.cpp

size.pass.cpp

map.cons/assign_initializer_list.pass.cpp

map.modifiers/emplace.pass.cpp

map.modifiers/emplace_hint.pass.cpp

map.modifiers/erase_key.pass.cpp

map.ops/count.pass.cpp

map.ops/equal_range.pass.cpp

map.ops/find.pass.cpp

map.ops/upper_bound.pass.cpp

clang-format

fix error

value_comp bad merge

_root cannot be redeclared

remove base and cast

copy_assign.pass.cpp

fails largely because of constexpr limit, because for  Container<int, MoveOnly> c, issues happen similar to move_alloc move_assign

use __node_traits::construct over placement new, copy_assing copy_alloc still pass

cf

note for failure

TODO

add constexpr cpp26

mistake

6 failures

something

clean

clean more

fix same_as allocate issues in index_rv_key

failures at move_alloc and move_assign

allocator for copy_assign

index_rv_key at it again

haxxx

Temporary solution for UB & restriction

copy_assign.pass.cpp

Finally only 2 tests fail

insert_key.pass.cpp

Move_alloc.pass.cpp fails

add docs

move_alloc and move_assign, fail in __insert_unique_from_orphaned_node, need to place the SFINAE there, not in __assign_value

kind of fixed it, almost

Fix for move_assign

almost a fix for move_assign.pass.cpp

insert_range_maps_sets.h, needs a lot of constexpr depth

add why sfinae

insert_and_emplace_allocator_requirements.pass.cpp passes

use the typedef

remove concepts, collapse unnecessary sfinae

some docs

breaks correctly

still correct failures with cleanup

more cleans

more clean

PR review comment

include __memory/construct_at

`Assertion `getConstructController()->isInAllocatorConstruct()' failed.`Revert "PR review comment"

This reverts commit 4fbb472.

Fails with:

```
  # .---command stderr------------
  # | t.tmp.exe: /home/runner/_work/llvm-project/llvm-project/libcxx/test/support/container_test_types.h:399: CopyInsertable<1>::CopyInsertable(const CopyInsertable<Dummy> &) [Dummy = 1]: Assertion `getConstructController()->isInAllocatorConstruct()' failed.
  # `-----------------------------
  # error: command failed with exit status: 250
```

one clean

cleanup for libcxx/test/support/container_test_types.h

clean back

clang-format

adjust constexpr steps arg

clean

Redundant check

Add ReleaseNotes

use allocator as template arg and allocator_traits, tests passed in cpp26

cf

hide from abi

Attempt fix for gcc-15 std=c++26

try

format and arm fix attempt'

cf

fix non-ascii

=default;

noop

abi

constexpr-dtor

WIP: gcc-15 failure investigation

fix the first failure with ptr_ is uninitialized

fix map

revert min_allocator default construction

_ptr is not initialized

use allocator as template arg and allocator_traits, tests passed in cpp26

remove UB using list

cf

doc-fix

Replace __value_ with __get_value() for __tree_node

miss typo

fix ctor for cpp03 buffer

cf

rename in map as well

cf

include

more?

hide from abi

terser

redundant launder

single branch

remove the & from buffer

remove _LIBCPP_STANDALONE_DEBUG

cf

disable test for g++-15

remove debugging attempts

Remove debugging attempt

Fix testing at runtime as well

Description and links

partial fix for }

restore TEST_HAS_NO_EXCEPTIONS

Remove extra include

remove set -x

undo debug attempts

Refactor libcxx/test/std/containers/associative/map/map.modifiers/insert_range.pass.cpp

CWG1514: key() is not constexpr

static can't be constexpr

Refactor libcxx/test/std/containers/associative/map/map.cons/from_range.pass.cpp

Refactor libcxx/test/std/containers/associative/map/map.cons/copy_alloc.pass.cpp

Refactor libcxx/test/std/containers/associative/map/map.cons/copy.pass.cpp

Refactor libcxx/test/std/containers/associative/map/map.access/index_rv_key.pass.cpp

Refactor libcxx/test/std/containers/associative/map/map.access/index_key.pass.cpp

grammar

Pass the generic-hardening-mode-debug

cf and remove non-ascii

Remove hide abi

obsolete comment

Add FIXME

Apply cf

cf

add constexpr

cf

Move ReleaseNotes to Implemented papers

Fix order of annotations

node-handle doc

unrelated defaulting

undo previous

unnecessary destructor for __tree_node_base

Remove constexpr from cpp03 code

Unnecessary annotation on deleted function

simplify type_trait

Allow runtime decision for __insert_unique_from_orphaned_node

Allow runtime decision for __assign_value

local cf

Simplify at.pass.cpp

use TEST_IS_CONSTANT_EVALUATED over libcxx function

Remove extra arm CI hack

missing space

Avoid creating a __tmp

explicit copy

Remove constexpr annotations from multimap

CI fix for clang <=20

Check clang<20 only for clang based compilers

Fix apple-clang macro lookup

Fixme, not todo

Updated FIXME

Remove assert(test());

clang-format?

Synopsis attach:  // constexpr since C++26

Revert "Remove assert(test());"

This reverts commit 9f931f5.

Fix the sed script

Author: vinay-deshmukh

libcxx/docs/FeatureTestMacroTable.rst

@@ -198,10 +198,6 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_char8_t``                                      ``201907L``
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_common_reference``                             ``202302L``
-    ---------------------------------------------------------- -----------------
-    ``__cpp_lib_common_reference_wrapper``                     ``202302L``
-    ---------------------------------------------------------- -----------------
     ``__cpp_lib_concepts``                                     ``202002L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_algorithms``                         ``201806L``
@@ -380,7 +376,7 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_ranges_iota``                                  ``202202L``
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_ranges_join_with``                             ``202202L``
+    ``__cpp_lib_ranges_join_with``                             *unimplemented*
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_ranges_repeat``                                ``202207L``
     ---------------------------------------------------------- -----------------
@@ -418,8 +414,6 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_atomic_min_max``                               *unimplemented*
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_atomic_ref``                                   ``202411L``
-    ---------------------------------------------------------- -----------------
     ``__cpp_lib_bind_front``                                   ``202306L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_bitset``                                       ``202306L``
@@ -430,11 +424,13 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_list``                               ``202502L``
     ---------------------------------------------------------- -----------------
+    ``__cpp_lib_constexpr_map``                                ``202502L``
+    ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_new``                                ``202406L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_queue``                              ``202502L``
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_constrained_equality``                         ``202411L``
+    ``__cpp_lib_constrained_equality``                         *unimplemented*
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_copyable_function``                            *unimplemented*
     ---------------------------------------------------------- -----------------
@@ -482,16 +478,14 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_not_fn``                                       ``202306L``
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_optional_range_support``                       ``202406L``
+    ``__cpp_lib_optional_range_support``                       *unimplemented*
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_out_ptr``                                      ``202311L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_philox_engine``                                *unimplemented*
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_ranges_concat``                                *unimplemented*
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_ranges_indices``                               ``202506L``
-    ---------------------------------------------------------- -----------------
     ``__cpp_lib_ratio``                                        ``202306L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_rcu``                                          *unimplemented*
@@ -510,8 +504,6 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_sstream_from_string_view``                     ``202306L``
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_string_subview``                               ``202506L``
-    ---------------------------------------------------------- -----------------
     ``__cpp_lib_string_view``                                  ``202403L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_submdspan``                                    *unimplemented*

libcxx/docs/ReleaseNotes/22.rst

@@ -40,11 +40,8 @@ Implemented Papers
 
 - P2321R2: ``zip`` (`Github <https://llvm.org/PR105169>`__) (The paper is partially implemented. ``zip_transform_view``
   is implemented in this release)
-- P3044R2: sub-``string_view`` from ``string`` (`Github <https://llvm.org/PR148140>`__)
-- P3223R2: Making ``std::istream::ignore`` less surprising (`Github <https://llvm.org/PR148178>`__)
-- P3060R3: Add ``std::views::indices(n)`` (`Github <https://llvm.org/PR148175>`__)
-- P2835R7: Expose ``std::atomic_ref``'s object address (`Github <https://llvm.org/PR118377>`__)
 - P3168R2: Give ``std::optional`` Range Support (`Github <https://llvm.org/PR105430>`__)
+- P3372R3: ``constexpr map`` (`Github <https://llvm.org/PR134330>`__) (The paper is partially implemented. ``constexpr map`` is implemented in this release)
 
 Improvements and New Features
 -----------------------------
@@ -67,14 +64,6 @@ Improvements and New Features
 - Multiple internal types have been refactored to use ``[[no_unique_address]]``, resulting in faster compile times and
   reduced debug information.
 
-- The performance of ``std::find`` has been improved by up to 2x for integral types
-- The ``std::distance`` and ``std::ranges::distance`` algorithms have been optimized for segmented iterators (e.g.,
-  ``std::join_view`` iterators), reducing the complexity from ``O(n)`` to ``O(n / segment_size)``. Benchmarks show
-  performance improvements of over 1600x in favorable cases with large segment sizes (e.g., 1024).
-- The ``std::{fill, fill_n}`` and ``std::ranges::{fill, fill_n}`` algorithms have been optimized for segmented iterators,
-  resulting in a performance improvement of at least 10x for ``std::deque<int>`` iterators and
-  ``std::join_view<std::vector<std::vector<int>>>`` iterators.
-
 Deprecations and Removals
 -------------------------
 

libcxx/include/__iterator/erase_if_container.h

@@ -22,7 +22,8 @@ _LIBCPP_PUSH_MACROS
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Container, class _Predicate>
-_LIBCPP_HIDE_FROM_ABI typename _Container::size_type __libcpp_erase_if_container(_Container& __c, _Predicate& __pred) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 typename _Container::size_type
+__libcpp_erase_if_container(_Container& __c, _Predicate& __pred) {
   typename _Container::size_type __old_size = __c.size();
 
   const typename _Container::iterator __last = __c.end();

libcxx/include/__node_handle

@@ -30,30 +30,30 @@ private:
 
 public:
   // [container.node.cons], constructors, copy, and assignment
-  constexpr node-handle() noexcept : ptr_(), alloc_() {}
-  node-handle(node-handle&&) noexcept;
-  node-handle& operator=(node-handle&&);
+  constexpr node-handle() noexcept : ptr_(), alloc_() {} // constexpr since C++26
+  node-handle(node-handle&&) noexcept; // constexpr since C++26
+  node-handle& operator=(node-handle&&); // constexpr since C++26
 
   // [container.node.dtor], destructor
-  ~node-handle();
+  ~node-handle(); // constexpr since C++26
 
   // [container.node.observers], observers
   value_type& value() const;            // not present for map containers
   key_type& key() const;                // not present for set containers
-  mapped_type& mapped() const;          // not present for set containers
+  mapped_type& mapped() const;          // not present for set containers // constexpr since C++26
 
-  allocator_type get_allocator() const;
-  explicit operator bool() const noexcept;
-  [[nodiscard]] bool empty() const noexcept; // nodiscard since C++20
+  allocator_type get_allocator() const; // constexpr since C++26
+  explicit operator bool() const noexcept; // constexpr since C++26
+  [[nodiscard]] bool empty() const noexcept; // nodiscard since C++20 // constexpr since C++26
 
   // [container.node.modifiers], modifiers
   void swap(node-handle&)
     noexcept(ator_traits::propagate_on_container_swap::value ||
-             ator_traits::is_always_equal::value);
+             ator_traits::is_always_equal::value); // constexpr since C++26
 
   friend void swap(node-handle& x, node-handle& y) noexcept(noexcept(x.swap(y))) {
     x.swap(y);
-  }
+  } // constexpr since C++26
 };
 
 */
@@ -99,12 +99,12 @@ private:
   __node_pointer_type __ptr_ = nullptr;
   optional<allocator_type> __alloc_;
 
-  _LIBCPP_HIDE_FROM_ABI void __release_ptr() {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void __release_ptr() {
     __ptr_   = nullptr;
     __alloc_ = std::nullopt;
   }
 
-  _LIBCPP_HIDE_FROM_ABI void __destroy_node_pointer() {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void __destroy_node_pointer() {
     if (__ptr_ != nullptr) {
       typedef typename __allocator_traits_rebind< allocator_type, _NodeType>::type __node_alloc_type;
       __node_alloc_type __alloc(*__alloc_);
@@ -113,19 +113,20 @@ private:
     }
   }
 
-  _LIBCPP_HIDE_FROM_ABI __basic_node_handle(__node_pointer_type __ptr, allocator_type const& __alloc)
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26
+  __basic_node_handle(__node_pointer_type __ptr, allocator_type const& __alloc)
       : __ptr_(__ptr), __alloc_(__alloc) {}
 
 public:
-  _LIBCPP_HIDE_FROM_ABI __basic_node_handle() = default;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 __basic_node_handle() = default;
 
-  _LIBCPP_HIDE_FROM_ABI __basic_node_handle(__basic_node_handle&& __other) noexcept
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 __basic_node_handle(__basic_node_handle&& __other) noexcept
       : __ptr_(__other.__ptr_), __alloc_(std::move(__other.__alloc_)) {
     __other.__ptr_   = nullptr;
     __other.__alloc_ = std::nullopt;
   }
 
-  _LIBCPP_HIDE_FROM_ABI __basic_node_handle& operator=(__basic_node_handle&& __other) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 __basic_node_handle& operator=(__basic_node_handle&& __other) {
     _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
         __alloc_ == std::nullopt || __alloc_traits::propagate_on_container_move_assignment::value ||
             __alloc_ == __other.__alloc_,
@@ -144,13 +145,13 @@ public:
     return *this;
   }
 
-  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const { return *__alloc_; }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 allocator_type get_allocator() const { return *__alloc_; }
 
-  _LIBCPP_HIDE_FROM_ABI explicit operator bool() const { return __ptr_ != nullptr; }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 explicit operator bool() const { return __ptr_ != nullptr; }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool empty() const { return __ptr_ == nullptr; }
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool empty() const { return __ptr_ == nullptr; }
 
-  _LIBCPP_HIDE_FROM_ABI void swap(__basic_node_handle& __other) noexcept(
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void swap(__basic_node_handle& __other) noexcept(
       __alloc_traits::propagate_on_container_swap::value || __alloc_traits::is_always_equal::value) {
     using std::swap;
     swap(__ptr_, __other.__ptr_);
@@ -159,12 +160,12 @@ public:
       swap(__alloc_, __other.__alloc_);
   }
 
-  _LIBCPP_HIDE_FROM_ABI friend void
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 friend void
   swap(__basic_node_handle& __a, __basic_node_handle& __b) noexcept(noexcept(__a.swap(__b))) {
     __a.swap(__b);
   }
 
-  _LIBCPP_HIDE_FROM_ABI ~__basic_node_handle() { __destroy_node_pointer(); }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 ~__basic_node_handle() { __destroy_node_pointer(); }
 };
 
 template <class _NodeType, class _Derived>
@@ -179,6 +180,7 @@ struct __map_node_handle_specifics {
   using key_type    = __remove_const_t<typename _NodeType::__node_value_type::first_type>;
   using mapped_type = typename _NodeType::__node_value_type::second_type;
 
+  // This method is not constexpr as per the standard.
   _LIBCPP_HIDE_FROM_ABI key_type& key() const {
     return const_cast<key_type&>(static_cast<_Derived const*>(this)->__ptr_->__get_value().first);
   }