From 31240ba0d8aff815dfb4cf90eab290805b921cbc Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Sat, 24 Aug 2024 23:52:42 +0300
Subject: [PATCH 01/13] [libc++][type_traits] P2647R1: A trait for implicit
 lifetime types

Implements P2674R1: https://wg21.link/P2674R1

- https://eel.is/c++draft/type.traits
  - https://eel.is/c++draft/meta.type.synop
  - https://eel.is/c++draft/meta.unary.prop
- https://eel.is/c++draft/support.limits
  - https://eel.is/c++draft/version.syn

Implementation details:
- Uses compiler intrinsic `__builtin_is_implicit_lifetime`:
  - https://github.com/llvm/llvm-project/pull/101807
- Tests based on:
    - https://github.com/llvm/llvm-project/blob/d213981c80626698a07b11ce872acba098a863d4/clang/test/SemaCXX/type-traits.cpp#L1989

References:
- Implicit-lifetime
  - Implicit-lifetime types [basic.types.general]/9: https://eel.is/c++draft/basic.types.general
  - Implicit-lifetime class [class.prop]/9: https://eel.is/c++draft/class.prop
- P0593R6 Implicit creation of objects for low-level object manipulation: https://wg21.link/P0593R6
- P1010R1 Container support for implicit lifetime types: https://wg21.link/P1010R1
- P0593R6 Implicit creation of objects for low-level object manipulation: https://wg21.link/P0593R6

Closes: #105259
---
 libcxx/include/CMakeLists.txt                 |   1 +
 .../__type_traits/is_implicit_lifetime.h      |  50 +++
 libcxx/include/type_traits                    |   8 +
 .../is_implicit_lifetime.pass.cpp             | 361 ++++++++++++++++++
 .../is_implicit_lifetime.verify.cpp           |  37 ++
 5 files changed, 457 insertions(+)
 create mode 100644 libcxx/include/__type_traits/is_implicit_lifetime.h
 create mode 100644 libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
 create mode 100644 libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp

diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index 32579272858a8..6c755e90214b4 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -778,6 +778,7 @@ set(files
   __type_traits/is_floating_point.h
   __type_traits/is_function.h
   __type_traits/is_fundamental.h
+  __type_traits/is_implicit_lifetime.h
   __type_traits/is_implicitly_default_constructible.h
   __type_traits/is_integral.h
   __type_traits/is_literal_type.h
diff --git a/libcxx/include/__type_traits/is_implicit_lifetime.h b/libcxx/include/__type_traits/is_implicit_lifetime.h
new file mode 100644
index 0000000000000..4cd593ebdbda6
--- /dev/null
+++ b/libcxx/include/__type_traits/is_implicit_lifetime.h
@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+// 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___TYPE_TRAITS_IS_IMPLICIT_LIFETIME_H
+#define _LIBCPP___TYPE_TRAITS_IS_IMPLICIT_LIFETIME_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER >= 23
+#  if __has_builtin(__builtin_is_implicit_lifetime)
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_implicit_lifetime : public bool_constant<__builtin_is_implicit_lifetime(_Tp)> {};
+
+template <class _Tp>
+inline constexpr bool is_implicit_lifetime_v = __builtin_is_implicit_lifetime(_Tp);
+
+#  else
+
+template <typename _Tp>
+struct is_implicit_lifetime
+    : std::disjunction< std::is_scalar<_Tp>,
+                        std::is_array<_Tp>,
+                        std::is_aggregate<_Tp>,
+                        std::conjunction< std::is_trivially_destructible<_Tp>,
+                                          std::disjunction< std::is_trivially_default_constructible<_Tp>,
+                                                            std::is_trivially_copy_constructible<_Tp>,
+                                                            std::is_trivially_move_constructible<_Tp>>>> {};
+
+template <class _Tp>
+inline constexpr bool is_implicit_lifetime_v = is_implicit_lifetime<_Tp>::value;
+
+#  endif
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_IMPLICIT_LIFETIME_H
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
index 5937d4fdc9e1a..d29721a371c39 100644
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -137,6 +137,8 @@ namespace std
     template <class T>                struct is_nothrow_swappable;      // C++17
     template <class T>                struct is_nothrow_destructible;
 
+    template<class T> struct is_implicit_lifetime;                     // Since C++23
+
     template <class T> struct has_virtual_destructor;
 
     template<class T> struct has_unique_object_representations;         // C++17
@@ -374,6 +376,8 @@ namespace std
         = is_nothrow_swappable<T>::value;                               // C++17
       template <class T> inline constexpr bool is_nothrow_destructible_v
         = is_nothrow_destructible<T>::value;                             // C++17
+      template<class T>
+        constexpr bool is_implicit_lifetime_v = is_implicit_lifetime<T>::value;   // Since C++23
       template <class T> inline constexpr bool has_virtual_destructor_v
         = has_virtual_destructor<T>::value;                              // C++17
       template<class T> inline constexpr bool has_unique_object_representations_v // C++17
@@ -517,6 +521,10 @@ namespace std
 #  include <__type_traits/unwrap_ref.h>
 #endif
 
+#if _LIBCPP_STD_VER >= 23
+#  include <__type_traits/is_implicit_lifetime.h>
+#endif
+
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
new file mode 100644
index 0000000000000..7a6af8ba28d80
--- /dev/null
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -0,0 +1,361 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <type_traits>
+
+// template<class T> struct is_implicit_lifetime;
+
+#include <cassert>
+#include <cstddef>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+
+#include "test_macros.h"
+
+enum Enum { EV };
+enum SignedEnum : signed int {};
+enum UnsignedEnum : unsigned int {};
+
+enum class EnumClass { EV };
+enum class SignedEnumClass : signed int {};
+enum class UnsignedEnumClass : unsigned int {};
+
+struct EmptyStruct {};
+struct IncompleteStruct;
+
+struct NoEligibleTrivialContructor {
+  NoEligibleTrivialContructor() {};
+  NoEligibleTrivialContructor(const NoEligibleTrivialContructor&) {}
+  NoEligibleTrivialContructor(NoEligibleTrivialContructor&&) {}
+};
+
+struct OnlyDefaultConstructorIsTrivial {
+  OnlyDefaultConstructorIsTrivial() = default;
+  OnlyDefaultConstructorIsTrivial(const OnlyDefaultConstructorIsTrivial&) {}
+  OnlyDefaultConstructorIsTrivial(OnlyDefaultConstructorIsTrivial&&) {}
+};
+
+struct AllContstructorsAreTrivial {
+  AllContstructorsAreTrivial()                                  = default;
+  AllContstructorsAreTrivial(const AllContstructorsAreTrivial&) = default;
+  AllContstructorsAreTrivial(AllContstructorsAreTrivial&&)      = default;
+};
+
+struct InheritedNoEligibleTrivialConstructor : NoEligibleTrivialContructor {
+  using NoEligibleTrivialContructor::NoEligibleTrivialContructor;
+};
+
+struct InheritedOnlyDefaultConstructorIsTrivial : OnlyDefaultConstructorIsTrivial {
+  using OnlyDefaultConstructorIsTrivial::OnlyDefaultConstructorIsTrivial;
+};
+
+struct InheritedAllContstructorsAreTrivial : AllContstructorsAreTrivial {
+  using AllContstructorsAreTrivial::AllContstructorsAreTrivial;
+};
+
+struct UserDeclaredDestructor {
+  ~UserDeclaredDestructor() = default;
+};
+
+struct UserProvidedDestructor {
+  ~UserProvidedDestructor() {}
+};
+
+struct UserDeletedDestructorInAggregate {
+  ~UserDeletedDestructorInAggregate() = delete;
+};
+
+struct UserDeletedDestructorInNonAggregate {
+  virtual void NonAggregate();
+  ~UserDeletedDestructorInNonAggregate() = delete;
+};
+
+struct DeletedDestructorViaBaseInAggregate : UserDeletedDestructorInAggregate {};
+struct DeletedDestructorViaBaseInNonAggregate : UserDeletedDestructorInNonAggregate {};
+
+template <bool B>
+struct ConstrainedUserDeclaredDefaultConstructor {
+  ConstrainedUserDeclaredDefaultConstructor()
+    requires B
+  = default;
+  ConstrainedUserDeclaredDefaultConstructor(const ConstrainedUserDeclaredDefaultConstructor&) {}
+};
+
+template <bool B>
+struct ConstrainedUserProvidedDestructor {
+  ~ConstrainedUserProvidedDestructor() = default;
+  ~ConstrainedUserProvidedDestructor()
+    requires B
+  {}
+};
+
+struct StructWithFlexibleArrayMember {
+  int arr[];
+};
+
+struct StructWithZeroSizedArray {
+  int arr[0];
+};
+
+#ifdef TEST_COMPILER_CLANG
+// typedef int *align_value_int __attribute__((align_value(16)));
+using AlignValueInt = int* __attribute__((align_value(16)));
+// typedef float float4 __attribute__((ext_vector_type(4)));
+using Float4 = float __attribute__((ext_vector_type(4)));
+
+struct [[clang::enforce_read_only_placement]] EnforceReadOnlyPlacement {};
+struct [[clang::type_visibility("hidden")]] TypeVisibility {};
+#endif
+
+// Test implicit-lifetime type
+template <typename T, bool Expected>
+constexpr void test_is_implicit_lifetime() {
+  static_assert(std::is_implicit_lifetime<T>::value == Expected);
+
+  // Runtime check
+  assert(std::is_implicit_lifetime_v<T> == Expected);
+}
+
+// Test pointer, reference, array, etc. types
+template <typename T>
+constexpr void test_is_implicit_lifetime() {
+  test_is_implicit_lifetime<T, true>();
+
+  // cv-qualified
+  test_is_implicit_lifetime<const T, true>();
+  test_is_implicit_lifetime<volatile T, true>();
+
+  test_is_implicit_lifetime<T&, false>();
+  test_is_implicit_lifetime<T&&, false>();
+
+  // Pointer types
+  test_is_implicit_lifetime<T*, true>();
+  test_is_implicit_lifetime<T* __restrict, true>();
+
+  // Arrays
+  test_is_implicit_lifetime<T[], true>();
+  test_is_implicit_lifetime<T[0], true>();
+  test_is_implicit_lifetime<T[94], true>();
+}
+
+// #ifdef TEST_COMPILER_CLANG
+// // Test language extensions: attributes
+// template <typename T>
+// constexpr void test_is_implicit_lifetime_with_attributes() {
+//   test_is_implicit_lifetime<T [[clang::annotate_type("category2")]]*, true>();
+//   test_is_implicit_lifetime<T __attribute__((btf_type_tag("user")))*, true>();
+//   static_assert(__builtin_is_implicit_lifetime(int __attribute__((btf_type_tag("user"))) *));
+
+//   test_is_implicit_lifetime<T __attribute__((noderef))*, true>();
+
+//   test_is_implicit_lifetime<T* _Nonnull, true>();
+//   test_is_implicit_lifetime<T* _Null_unspecified, true>();
+//   test_is_implicit_lifetime<T* _Nullable, true>();
+// }
+// #endif // TEST_COMPILER_CLANG
+
+constexpr bool test() {
+  // Standard fundamental C++ types
+
+  test_is_implicit_lifetime<decltype(nullptr), true>();
+  test_is_implicit_lifetime<std::nullptr_t, true>();
+
+  test_is_implicit_lifetime<void, false>();
+  test_is_implicit_lifetime<const void, false>();
+  test_is_implicit_lifetime<volatile void, false>();
+
+  test_is_implicit_lifetime<bool>();
+
+  test_is_implicit_lifetime<char>();
+  test_is_implicit_lifetime<signed char>();
+  test_is_implicit_lifetime<unsigned char>();
+
+#if !defined(TEST_HAS_NO_WIDE_CHARACTERS)
+  test_is_implicit_lifetime<wchar_t>();
+#endif
+
+#if !defined(TEST_HAS_NO_CHAR8_T)
+  test_is_implicit_lifetime<char8_t>();
+#endif
+  test_is_implicit_lifetime<char16_t>();
+  test_is_implicit_lifetime<char32_t>();
+
+  // test_is_implicit_lifetime<int, true>();
+  // test_is_implicit_lifetime<int&, false>();
+  // test_is_implicit_lifetime<int&&, false>();
+
+  // test_is_implicit_lifetime<int*, true>();
+  // test_is_implicit_lifetime<int[], true>();
+  // test_is_implicit_lifetime<int[0], true>();
+  // test_is_implicit_lifetime<int[94], true>();
+  test_is_implicit_lifetime<short>();
+  test_is_implicit_lifetime<short int>();
+  test_is_implicit_lifetime<signed short>();
+  test_is_implicit_lifetime<signed short int>();
+  test_is_implicit_lifetime<unsigned short>();
+  test_is_implicit_lifetime<unsigned short int>();
+  test_is_implicit_lifetime<int>();
+  test_is_implicit_lifetime<signed>();
+  test_is_implicit_lifetime<signed int>();
+  test_is_implicit_lifetime<unsigned>();
+  test_is_implicit_lifetime<unsigned int>();
+  test_is_implicit_lifetime<long>();
+  test_is_implicit_lifetime<long int>();
+  test_is_implicit_lifetime<signed long>();
+  test_is_implicit_lifetime<signed long int>();
+  test_is_implicit_lifetime<unsigned long>();
+  test_is_implicit_lifetime<unsigned long int>();
+  test_is_implicit_lifetime<long long>();
+  test_is_implicit_lifetime<long long int>();
+  test_is_implicit_lifetime<signed long long>();
+  test_is_implicit_lifetime<signed long long int>();
+  test_is_implicit_lifetime<unsigned long long>();
+  test_is_implicit_lifetime<unsigned long long int>();
+
+  test_is_implicit_lifetime<float>();
+  test_is_implicit_lifetime<double>();
+  test_is_implicit_lifetime<long double>();
+
+  test_is_implicit_lifetime<Enum>();
+  test_is_implicit_lifetime<SignedEnum>();
+  test_is_implicit_lifetime<UnsignedEnum>();
+
+  test_is_implicit_lifetime<EnumClass>();
+  test_is_implicit_lifetime<SignedEnumClass>();
+  test_is_implicit_lifetime<UnsignedEnumClass>();
+
+  test_is_implicit_lifetime<void(), false>();
+  test_is_implicit_lifetime<void()&, false>();
+  test_is_implicit_lifetime<void() const, false>();
+  test_is_implicit_lifetime<void (&)(), false>();
+  test_is_implicit_lifetime<void (*)(), true>();
+
+  // test_is_implicit_lifetime<int UserDeclaredDestructor::*, true>();
+  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)(), true>();
+  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)() const, true>();
+  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)()&, true>();
+  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)()&&, true>();
+
+  // Implicit-lifetime class types
+
+  test_is_implicit_lifetime<EmptyStruct>();
+  test_is_implicit_lifetime<int EmptyStruct::*, true>(); // Pointer-to-member
+  test_is_implicit_lifetime<int (EmptyStruct::*)(), true>();
+  test_is_implicit_lifetime<int (EmptyStruct::*)() const, true>();
+  test_is_implicit_lifetime<int (EmptyStruct::*)()&, true>();
+  test_is_implicit_lifetime<int (EmptyStruct::*)()&&, true>();
+
+  test_is_implicit_lifetime<IncompleteStruct[], true>();
+  test_is_implicit_lifetime<IncompleteStruct[82], true>();
+
+  test_is_implicit_lifetime<UserDeclaredDestructor>();
+
+  test_is_implicit_lifetime<UserProvidedDestructor, false>();
+
+  test_is_implicit_lifetime<NoEligibleTrivialContructor, false>();
+
+  test_is_implicit_lifetime<OnlyDefaultConstructorIsTrivial, true>();
+
+  test_is_implicit_lifetime<AllContstructorsAreTrivial, true>();
+
+  test_is_implicit_lifetime<InheritedNoEligibleTrivialConstructor, false>();
+
+  test_is_implicit_lifetime<InheritedOnlyDefaultConstructorIsTrivial, true>();
+
+  test_is_implicit_lifetime<InheritedAllContstructorsAreTrivial, true>();
+
+  test_is_implicit_lifetime<UserDeletedDestructorInAggregate, true>();
+
+  test_is_implicit_lifetime<UserDeletedDestructorInNonAggregate, false>();
+
+  test_is_implicit_lifetime<DeletedDestructorViaBaseInAggregate, true>();
+
+  test_is_implicit_lifetime<DeletedDestructorViaBaseInNonAggregate, false>();
+
+  test_is_implicit_lifetime<ConstrainedUserDeclaredDefaultConstructor<true>, true>();
+  test_is_implicit_lifetime<ConstrainedUserDeclaredDefaultConstructor<false>, false>();
+
+  test_is_implicit_lifetime<ConstrainedUserProvidedDestructor<true>, false>();
+  test_is_implicit_lifetime<ConstrainedUserProvidedDestructor<false>, true>();
+
+  test_is_implicit_lifetime<StructWithFlexibleArrayMember, true>();
+
+  test_is_implicit_lifetime<StructWithZeroSizedArray, true>();
+
+  // C++ standard library types
+
+  test_is_implicit_lifetime<std::pair<int, float>>();
+  test_is_implicit_lifetime<std::tuple<int, float>>();
+
+  // Standard C types
+
+  test_is_implicit_lifetime<_Complex float>();
+  test_is_implicit_lifetime<_Complex double>();
+  test_is_implicit_lifetime<_Complex long double>();
+
+  // test_is_implicit_lifetime<_Imaginary float>();
+  // test_is_implicit_lifetime<_Imaginary double>();
+  // test_is_implicit_lifetime<_Imaginary long double>();
+
+  // Standard C23 types
+
+#ifdef TEST_COMPILER_CLANG
+  test_is_implicit_lifetime<_BitInt(8)>();
+  test_is_implicit_lifetime<_BitInt(128)>();
+#endif
+
+  // Language extensions: Types
+
+#if !defined(TEST_HAS_NO_INT128)
+  test_is_implicit_lifetime<__int128_t>();
+  test_is_implicit_lifetime<__uint128_t>();
+#endif
+
+  // #if  __STDC_VERSION__ >= 20
+  // #endif
+
+#ifdef TEST_COMPILER_CLANG
+  // https://clang.llvm.org/docs/LanguageExtensions.html#half-precision-floating-point
+  test_is_implicit_lifetime<__fp16>();
+  test_is_implicit_lifetime<__bf16>();
+#endif // TEST_COMPILER_CLANG
+
+  // Language extensions: Attributes
+
+#ifdef TEST_COMPILER_CLANG
+  test_is_implicit_lifetime<AlignValueInt, true>();
+  test_is_implicit_lifetime<Float4, true>();
+
+  test_is_implicit_lifetime<EnforceReadOnlyPlacement, true>();
+  test_is_implicit_lifetime<TypeVisibility, true>();
+
+  // test_is_implicit_lifetime_with_attributes<int>();
+  // test_is_implicit_lifetime_with_attributes<float>();
+
+  test_is_implicit_lifetime<int [[clang::annotate_type("category2")]]*, true>();
+  test_is_implicit_lifetime<int __attribute__((btf_type_tag("user")))*, true>();
+
+  test_is_implicit_lifetime<int __attribute__((noderef))*, true>();
+
+  test_is_implicit_lifetime<int* _Nonnull, true>();
+  test_is_implicit_lifetime<int* _Null_unspecified, true>();
+  test_is_implicit_lifetime<int* _Nullable, true>();
+#endif // TEST_COMPILER_CLANG
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
new file mode 100644
index 0000000000000..c557731b91a67
--- /dev/null
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <type_traits>
+
+// template<class T> struct is_implicit_lifetime;
+
+#include <cassert>
+#include <cstddef>
+#include <type_traits>
+
+#include "test_macros.h"
+
+struct IncompleteStruct;
+
+// expected-error@*:* {{incomplete type 'IncompleteStruct' used in type trait expression}}
+static_assert(!std::is_implicit_lifetime<IncompleteStruct>::value);
+
+// expected-error@*:* {{atomic types are not supported in '__builtin_is_implicit_lifetime'}}
+static_assert(!std::is_implicit_lifetime<_Atomic int>::value);
+
+#if 0
+// FIXME: "variable length arrays in C++ are a Clang extension"
+void test(int n) {
+  int varArr[n];
+  using VarArrT = decltype(varArr);
+  // expected-error@*:* {{variable length arrays are not supported in '__builtin_is_implicit_lifetime'}}
+  static_assert(std::is_implicit_lifetime<VarArrT>::value);
+}
+#endif

From c8ae04b9c1519d2050fd01572dd30846d712e160 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Sat, 31 Aug 2024 23:18:20 +0300
Subject: [PATCH 02/13] Cleanup + FTM

---
 libcxx/docs/FeatureTestMacroTable.rst         |  2 +
 libcxx/docs/ReleaseNotes/20.rst               |  1 +
 libcxx/docs/Status/Cxx23Papers.csv            |  2 +-
 .../__type_traits/is_implicit_lifetime.h      | 15 ------
 libcxx/include/module.modulemap               |  1 +
 libcxx/include/version                        |  4 ++
 libcxx/modules/std/type_traits.inc            |  8 +++-
 .../type_traits.version.compile.pass.cpp      | 43 +++++++++++++++++
 .../version.version.compile.pass.cpp          | 43 +++++++++++++++++
 .../is_implicit_lifetime.pass.cpp             | 48 ++-----------------
 .../is_implicit_lifetime.verify.cpp           | 22 ++++-----
 .../generate_feature_test_macro_components.py |  7 +++
 12 files changed, 122 insertions(+), 74 deletions(-)

diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index c909a4300db1a..05b08da521535 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -336,6 +336,8 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_ios_noreplace``                                ``202207L``
     ---------------------------------------------------------- -----------------
+    ``__cpp_lib_is_implicit_lifetime``                         ``202302L``
+    ---------------------------------------------------------- -----------------
     ``__cpp_lib_is_scoped_enum``                               ``202011L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_mdspan``                                       ``202207L``
diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
index 93d6027291ad9..cb95d7059eb83 100644
--- a/libcxx/docs/ReleaseNotes/20.rst
+++ b/libcxx/docs/ReleaseNotes/20.rst
@@ -41,6 +41,7 @@ Implemented Papers
 - P2747R2: ``constexpr`` placement new (`Github <https://github.com/llvm/llvm-project/issues/105427>`__)
 - P2609R3: Relaxing Ranges Just A Smidge (`Github <https://github.com/llvm/llvm-project/issues/105253>`__)
 - P2985R0: A type trait for detecting virtual base classes (`Github <https://github.com/llvm/llvm-project/issues/105432>`__)
+- P2674R1: A trait for implicit lifetime types (`Github <https://github.com/llvm/llvm-project/issues/105259>`__)
 
 
 Improvements and New Features
diff --git a/libcxx/docs/Status/Cxx23Papers.csv b/libcxx/docs/Status/Cxx23Papers.csv
index 2c8a91d8401b5..2cf63b29ab53b 100644
--- a/libcxx/docs/Status/Cxx23Papers.csv
+++ b/libcxx/docs/Status/Cxx23Papers.csv
@@ -113,7 +113,7 @@
 "`P2572R1 <https://wg21.link/P2572R1>`__","``std::format`` fill character allowances","2023-02 (Issaquah)","|Complete|","17.0",""
 "`P2693R1 <https://wg21.link/P2693R1>`__","Formatting ``thread::id`` and ``stacktrace``","2023-02 (Issaquah)","|Partial|","","The formatter for ``stacktrace`` is not implemented, since ``stacktrace`` is not implemented yet"
 "`P2679R2 <https://wg21.link/P2679R2>`__","Fixing ``std::start_lifetime_as`` for arrays","2023-02 (Issaquah)","","",""
-"`P2674R1 <https://wg21.link/P2674R1>`__","A trait for implicit lifetime types","2023-02 (Issaquah)","","",""
+"`P2674R1 <https://wg21.link/P2674R1>`__","A trait for implicit lifetime types","2023-02 (Issaquah)","|Complete|","20.0",""
 "`P2655R3 <https://wg21.link/P2655R3>`__","``common_reference_t`` of ``reference_wrapper`` Should Be a Reference Type","2023-02 (Issaquah)","","",""
 "`P2652R2 <https://wg21.link/P2652R2>`__","Disallow User Specialization of ``allocator_traits``","2023-02 (Issaquah)","|Complete|","19.0",""
 "`P2787R1 <https://wg21.link/P2787R1>`__","``pmr::generator`` - Promise Types are not Values","2023-02 (Issaquah)","","",""
diff --git a/libcxx/include/__type_traits/is_implicit_lifetime.h b/libcxx/include/__type_traits/is_implicit_lifetime.h
index 4cd593ebdbda6..2aba420bd2b59 100644
--- a/libcxx/include/__type_traits/is_implicit_lifetime.h
+++ b/libcxx/include/__type_traits/is_implicit_lifetime.h
@@ -27,21 +27,6 @@ struct _LIBCPP_TEMPLATE_VIS is_implicit_lifetime : public bool_constant<__builti
 template <class _Tp>
 inline constexpr bool is_implicit_lifetime_v = __builtin_is_implicit_lifetime(_Tp);
 
-#  else
-
-template <typename _Tp>
-struct is_implicit_lifetime
-    : std::disjunction< std::is_scalar<_Tp>,
-                        std::is_array<_Tp>,
-                        std::is_aggregate<_Tp>,
-                        std::conjunction< std::is_trivially_destructible<_Tp>,
-                                          std::disjunction< std::is_trivially_default_constructible<_Tp>,
-                                                            std::is_trivially_copy_constructible<_Tp>,
-                                                            std::is_trivially_move_constructible<_Tp>>>> {};
-
-template <class _Tp>
-inline constexpr bool is_implicit_lifetime_v = is_implicit_lifetime<_Tp>::value;
-
 #  endif
 #endif
 
diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
index f193b5d95f49f..da3fa1cbaa66b 100644
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -1944,6 +1944,7 @@ module std_private_type_traits_is_final                                  [system
 module std_private_type_traits_is_floating_point                         [system] { header "__type_traits/is_floating_point.h" }
 module std_private_type_traits_is_function                               [system] { header "__type_traits/is_function.h" }
 module std_private_type_traits_is_fundamental                            [system] { header "__type_traits/is_fundamental.h" }
+module std_private_type_traits_is_implicit_lifetime                      [system] { header "__type_traits/is_implicit_lifetime.h" }
 module std_private_type_traits_is_implicitly_default_constructible       [system] {
   header "__type_traits/is_implicitly_default_constructible.h"
   export std_private_type_traits_integral_constant
diff --git a/libcxx/include/version b/libcxx/include/version
index dc1d3fd268ce8..482913b2759c9 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -138,6 +138,7 @@ __cpp_lib_ios_noreplace                                 202207L <ios>
 __cpp_lib_is_aggregate                                  201703L <type_traits>
 __cpp_lib_is_constant_evaluated                         201811L <type_traits>
 __cpp_lib_is_final                                      201402L <type_traits>
+__cpp_lib_is_implicit_lifetime                          202302L <type_traits>
 __cpp_lib_is_invocable                                  201703L <type_traits>
 __cpp_lib_is_layout_compatible                          201907L <type_traits>
 __cpp_lib_is_nothrow_convertible                        201806L <type_traits>
@@ -473,6 +474,9 @@ __cpp_lib_void_t                                        201411L <type_traits>
 # define __cpp_lib_forward_like                         202207L
 # define __cpp_lib_invoke_r                             202106L
 # define __cpp_lib_ios_noreplace                        202207L
+# if __has_builtin(__builtin_is_implicit_lifetime)
+#   define __cpp_lib_is_implicit_lifetime               202302L
+# endif
 # define __cpp_lib_is_scoped_enum                       202011L
 # define __cpp_lib_mdspan                               202207L
 # define __cpp_lib_modules                              202207L
diff --git a/libcxx/modules/std/type_traits.inc b/libcxx/modules/std/type_traits.inc
index d368daf35ccb8..d7b5a7243746b 100644
--- a/libcxx/modules/std/type_traits.inc
+++ b/libcxx/modules/std/type_traits.inc
@@ -98,7 +98,9 @@ export namespace std {
 
   using std::is_nothrow_destructible;
 
-  //  using std::is_implicit_lifetime;
+#if _LIBCPP_STD_VER >= 23 && __has_builtin(__builtin_is_implicit_lifetime)
+  using std::is_implicit_lifetime;
+#endif
 
   using std::has_virtual_destructor;
 
@@ -243,7 +245,9 @@ export namespace std {
   using std::is_destructible_v;
   using std::is_empty_v;
   using std::is_final_v;
-  // using std::is_implicit_lifetime_v;
+#if _LIBCPP_STD_VER >= 23 && __has_builtin(__builtin_is_implicit_lifetime)
+  using std::is_implicit_lifetime_v;
+#endif
   using std::is_move_assignable_v;
   using std::is_move_constructible_v;
   using std::is_nothrow_assignable_v;
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/type_traits.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/type_traits.version.compile.pass.cpp
index 1cbf2699a95bc..d9d698ace2b65 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/type_traits.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/type_traits.version.compile.pass.cpp
@@ -23,6 +23,7 @@
     __cpp_lib_is_aggregate                         201703L [C++17]
     __cpp_lib_is_constant_evaluated                201811L [C++20]
     __cpp_lib_is_final                             201402L [C++14]
+    __cpp_lib_is_implicit_lifetime                 202302L [C++23]
     __cpp_lib_is_invocable                         201703L [C++17]
     __cpp_lib_is_layout_compatible                 201907L [C++20]
     __cpp_lib_is_nothrow_convertible               201806L [C++20]
@@ -75,6 +76,10 @@
 #   error "__cpp_lib_is_final should not be defined before c++14"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifdef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should not be defined before c++17"
 # endif
@@ -179,6 +184,10 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++14"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifdef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should not be defined before c++17"
 # endif
@@ -301,6 +310,10 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++17"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++17"
 # endif
@@ -444,6 +457,10 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++20"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++20"
 # endif
@@ -614,6 +631,19 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++23"
 # endif
 
+# if __has_builtin(__builtin_is_implicit_lifetime)
+#   ifndef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should be defined in c++23"
+#   endif
+#   if __cpp_lib_is_implicit_lifetime != 202302L
+#     error "__cpp_lib_is_implicit_lifetime should have the value 202302L in c++23"
+#   endif
+# else
+#   ifdef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should not be defined when the requirement '__has_builtin(__builtin_is_implicit_lifetime)' is not met!"
+#   endif
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++23"
 # endif
@@ -796,6 +826,19 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++26"
 # endif
 
+# if __has_builtin(__builtin_is_implicit_lifetime)
+#   ifndef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should be defined in c++26"
+#   endif
+#   if __cpp_lib_is_implicit_lifetime != 202302L
+#     error "__cpp_lib_is_implicit_lifetime should have the value 202302L in c++26"
+#   endif
+# else
+#   ifdef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should not be defined when the requirement '__has_builtin(__builtin_is_implicit_lifetime)' is not met!"
+#   endif
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++26"
 # endif
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
index a022c90e166c8..10cf69f67c39f 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
@@ -125,6 +125,7 @@
     __cpp_lib_is_aggregate                                  201703L [C++17]
     __cpp_lib_is_constant_evaluated                         201811L [C++20]
     __cpp_lib_is_final                                      201402L [C++14]
+    __cpp_lib_is_implicit_lifetime                          202302L [C++23]
     __cpp_lib_is_invocable                                  201703L [C++17]
     __cpp_lib_is_layout_compatible                          201907L [C++20]
     __cpp_lib_is_nothrow_convertible                        201806L [C++20]
@@ -671,6 +672,10 @@
 #   error "__cpp_lib_is_final should not be defined before c++14"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifdef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should not be defined before c++17"
 # endif
@@ -1550,6 +1555,10 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++14"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifdef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should not be defined before c++17"
 # endif
@@ -2564,6 +2573,10 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++17"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++17"
 # endif
@@ -3842,6 +3855,10 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++20"
 # endif
 
+# ifdef __cpp_lib_is_implicit_lifetime
+#   error "__cpp_lib_is_implicit_lifetime should not be defined before c++23"
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++20"
 # endif
@@ -5306,6 +5323,19 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++23"
 # endif
 
+# if __has_builtin(__builtin_is_implicit_lifetime)
+#   ifndef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should be defined in c++23"
+#   endif
+#   if __cpp_lib_is_implicit_lifetime != 202302L
+#     error "__cpp_lib_is_implicit_lifetime should have the value 202302L in c++23"
+#   endif
+# else
+#   ifdef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should not be defined when the requirement '__has_builtin(__builtin_is_implicit_lifetime)' is not met!"
+#   endif
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++23"
 # endif
@@ -7112,6 +7142,19 @@
 #   error "__cpp_lib_is_final should have the value 201402L in c++26"
 # endif
 
+# if __has_builtin(__builtin_is_implicit_lifetime)
+#   ifndef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should be defined in c++26"
+#   endif
+#   if __cpp_lib_is_implicit_lifetime != 202302L
+#     error "__cpp_lib_is_implicit_lifetime should have the value 202302L in c++26"
+#   endif
+# else
+#   ifdef __cpp_lib_is_implicit_lifetime
+#     error "__cpp_lib_is_implicit_lifetime should not be defined when the requirement '__has_builtin(__builtin_is_implicit_lifetime)' is not met!"
+#   endif
+# endif
+
 # ifndef __cpp_lib_is_invocable
 #   error "__cpp_lib_is_invocable should be defined in c++26"
 # endif
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 7a6af8ba28d80..2b8d00ea57745 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -8,6 +8,10 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
+// These compilers don't support __builtin_is_implicit_lifetime yet.
+// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-16, apple-clang-17
+// XFAIL: apple-clang
+
 // <type_traits>
 
 // template<class T> struct is_implicit_lifetime;
@@ -106,10 +110,8 @@ struct StructWithZeroSizedArray {
 };
 
 #ifdef TEST_COMPILER_CLANG
-// typedef int *align_value_int __attribute__((align_value(16)));
 using AlignValueInt = int* __attribute__((align_value(16)));
-// typedef float float4 __attribute__((ext_vector_type(4)));
-using Float4 = float __attribute__((ext_vector_type(4)));
+using Float4        = float __attribute__((ext_vector_type(4)));
 
 struct [[clang::enforce_read_only_placement]] EnforceReadOnlyPlacement {};
 struct [[clang::type_visibility("hidden")]] TypeVisibility {};
@@ -146,22 +148,6 @@ constexpr void test_is_implicit_lifetime() {
   test_is_implicit_lifetime<T[94], true>();
 }
 
-// #ifdef TEST_COMPILER_CLANG
-// // Test language extensions: attributes
-// template <typename T>
-// constexpr void test_is_implicit_lifetime_with_attributes() {
-//   test_is_implicit_lifetime<T [[clang::annotate_type("category2")]]*, true>();
-//   test_is_implicit_lifetime<T __attribute__((btf_type_tag("user")))*, true>();
-//   static_assert(__builtin_is_implicit_lifetime(int __attribute__((btf_type_tag("user"))) *));
-
-//   test_is_implicit_lifetime<T __attribute__((noderef))*, true>();
-
-//   test_is_implicit_lifetime<T* _Nonnull, true>();
-//   test_is_implicit_lifetime<T* _Null_unspecified, true>();
-//   test_is_implicit_lifetime<T* _Nullable, true>();
-// }
-// #endif // TEST_COMPILER_CLANG
-
 constexpr bool test() {
   // Standard fundamental C++ types
 
@@ -188,14 +174,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<char16_t>();
   test_is_implicit_lifetime<char32_t>();
 
-  // test_is_implicit_lifetime<int, true>();
-  // test_is_implicit_lifetime<int&, false>();
-  // test_is_implicit_lifetime<int&&, false>();
-
-  // test_is_implicit_lifetime<int*, true>();
-  // test_is_implicit_lifetime<int[], true>();
-  // test_is_implicit_lifetime<int[0], true>();
-  // test_is_implicit_lifetime<int[94], true>();
   test_is_implicit_lifetime<short>();
   test_is_implicit_lifetime<short int>();
   test_is_implicit_lifetime<signed short>();
@@ -238,12 +216,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<void (&)(), false>();
   test_is_implicit_lifetime<void (*)(), true>();
 
-  // test_is_implicit_lifetime<int UserDeclaredDestructor::*, true>();
-  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)(), true>();
-  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)() const, true>();
-  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)()&, true>();
-  // test_is_implicit_lifetime<int (UserDeclaredDestructor::*)()&&, true>();
-
   // Implicit-lifetime class types
 
   test_is_implicit_lifetime<EmptyStruct>();
@@ -301,10 +273,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<_Complex double>();
   test_is_implicit_lifetime<_Complex long double>();
 
-  // test_is_implicit_lifetime<_Imaginary float>();
-  // test_is_implicit_lifetime<_Imaginary double>();
-  // test_is_implicit_lifetime<_Imaginary long double>();
-
   // Standard C23 types
 
 #ifdef TEST_COMPILER_CLANG
@@ -319,9 +287,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<__uint128_t>();
 #endif
 
-  // #if  __STDC_VERSION__ >= 20
-  // #endif
-
 #ifdef TEST_COMPILER_CLANG
   // https://clang.llvm.org/docs/LanguageExtensions.html#half-precision-floating-point
   test_is_implicit_lifetime<__fp16>();
@@ -337,9 +302,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<EnforceReadOnlyPlacement, true>();
   test_is_implicit_lifetime<TypeVisibility, true>();
 
-  // test_is_implicit_lifetime_with_attributes<int>();
-  // test_is_implicit_lifetime_with_attributes<float>();
-
   test_is_implicit_lifetime<int [[clang::annotate_type("category2")]]*, true>();
   test_is_implicit_lifetime<int __attribute__((btf_type_tag("user")))*, true>();
 
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
index c557731b91a67..9a43d082f5093 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
@@ -8,30 +8,26 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
+// These compilers don't support __builtin_is_implicit_lifetime yet.
+// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-16, apple-clang-17
+// XFAIL: apple-clang
+
 // <type_traits>
 
 // template<class T> struct is_implicit_lifetime;
 
-#include <cassert>
-#include <cstddef>
 #include <type_traits>
 
-#include "test_macros.h"
-
 struct IncompleteStruct;
 
 // expected-error@*:* {{incomplete type 'IncompleteStruct' used in type trait expression}}
 static_assert(!std::is_implicit_lifetime<IncompleteStruct>::value);
 
+// expected-error@*:* {{incomplete type 'IncompleteStruct' used in type trait expression}}
+static_assert(!std::is_implicit_lifetime_v<IncompleteStruct>);
+
 // expected-error@*:* {{atomic types are not supported in '__builtin_is_implicit_lifetime'}}
 static_assert(!std::is_implicit_lifetime<_Atomic int>::value);
 
-#if 0
-// FIXME: "variable length arrays in C++ are a Clang extension"
-void test(int n) {
-  int varArr[n];
-  using VarArrT = decltype(varArr);
-  // expected-error@*:* {{variable length arrays are not supported in '__builtin_is_implicit_lifetime'}}
-  static_assert(std::is_implicit_lifetime<VarArrT>::value);
-}
-#endif
+// expected-error@*:* {{atomic types are not supported in '__builtin_is_implicit_lifetime'}}
+static_assert(!std::is_implicit_lifetime_v<_Atomic int>);
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index 3bdd3adad15b4..1f5a6b22b47de 100755
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -742,6 +742,13 @@ def add_version_header(tc):
             "values": {"c++14": 201402},
             "headers": ["type_traits"],
         },
+        {
+            "name": "__cpp_lib_is_implicit_lifetime",
+            "values": {"c++23": 202302},
+            "headers": ["type_traits"],
+            "test_suite_guard": "__has_builtin(__builtin_is_implicit_lifetime)",
+            "libcxx_guard": "__has_builtin(__builtin_is_implicit_lifetime)",
+        },
         {
             "name": "__cpp_lib_is_invocable",
             "values": {"c++17": 201703},

From 25e6e5e1e373228593d700648168630e50abb920 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Tue, 3 Sep 2024 21:53:47 +0300
Subject: [PATCH 03/13] Address a review comment

---
 .../meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp  | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 2b8d00ea57745..4abae28e1cf27 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -120,9 +120,7 @@ struct [[clang::type_visibility("hidden")]] TypeVisibility {};
 // Test implicit-lifetime type
 template <typename T, bool Expected>
 constexpr void test_is_implicit_lifetime() {
-  static_assert(std::is_implicit_lifetime<T>::value == Expected);
-
-  // Runtime check
+  assert(std::is_implicit_lifetime<T>::value == Expected);
   assert(std::is_implicit_lifetime_v<T> == Expected);
 }
 

From b1eb87aaa4979aaa99a9a92b5600efc557a8bbc5 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Thu, 5 Sep 2024 16:11:14 +0300
Subject: [PATCH 04/13] Addressed review comments

---
 .../is_implicit_lifetime.pass.cpp             | 44 +------------------
 .../is_implicit_lifetime.verify.cpp           |  5 ++-
 2 files changed, 4 insertions(+), 45 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 4abae28e1cf27..8052fcb64a54b 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -9,8 +9,7 @@
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
 // These compilers don't support __builtin_is_implicit_lifetime yet.
-// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-16, apple-clang-17
-// XFAIL: apple-clang
+// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-15, apple-clang-16, apple-clang-17
 
 // <type_traits>
 
@@ -109,14 +108,6 @@ struct StructWithZeroSizedArray {
   int arr[0];
 };
 
-#ifdef TEST_COMPILER_CLANG
-using AlignValueInt = int* __attribute__((align_value(16)));
-using Float4        = float __attribute__((ext_vector_type(4)));
-
-struct [[clang::enforce_read_only_placement]] EnforceReadOnlyPlacement {};
-struct [[clang::type_visibility("hidden")]] TypeVisibility {};
-#endif
-
 // Test implicit-lifetime type
 template <typename T, bool Expected>
 constexpr void test_is_implicit_lifetime() {
@@ -142,7 +133,6 @@ constexpr void test_is_implicit_lifetime() {
 
   // Arrays
   test_is_implicit_lifetime<T[], true>();
-  test_is_implicit_lifetime<T[0], true>();
   test_is_implicit_lifetime<T[94], true>();
 }
 
@@ -278,38 +268,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<_BitInt(128)>();
 #endif
 
-  // Language extensions: Types
-
-#if !defined(TEST_HAS_NO_INT128)
-  test_is_implicit_lifetime<__int128_t>();
-  test_is_implicit_lifetime<__uint128_t>();
-#endif
-
-#ifdef TEST_COMPILER_CLANG
-  // https://clang.llvm.org/docs/LanguageExtensions.html#half-precision-floating-point
-  test_is_implicit_lifetime<__fp16>();
-  test_is_implicit_lifetime<__bf16>();
-#endif // TEST_COMPILER_CLANG
-
-  // Language extensions: Attributes
-
-#ifdef TEST_COMPILER_CLANG
-  test_is_implicit_lifetime<AlignValueInt, true>();
-  test_is_implicit_lifetime<Float4, true>();
-
-  test_is_implicit_lifetime<EnforceReadOnlyPlacement, true>();
-  test_is_implicit_lifetime<TypeVisibility, true>();
-
-  test_is_implicit_lifetime<int [[clang::annotate_type("category2")]]*, true>();
-  test_is_implicit_lifetime<int __attribute__((btf_type_tag("user")))*, true>();
-
-  test_is_implicit_lifetime<int __attribute__((noderef))*, true>();
-
-  test_is_implicit_lifetime<int* _Nonnull, true>();
-  test_is_implicit_lifetime<int* _Null_unspecified, true>();
-  test_is_implicit_lifetime<int* _Nullable, true>();
-#endif // TEST_COMPILER_CLANG
-
   return true;
 }
 
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
index 9a43d082f5093..657d84c5bc9da 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
@@ -9,8 +9,9 @@
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
 // These compilers don't support __builtin_is_implicit_lifetime yet.
-// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-16, apple-clang-17
-// XFAIL: apple-clang
+// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-15, apple-clang-16, apple-clang-17
+
+// ADDITIONAL_COMPILE_FLAGS: -Wno-vla, -Wno-zero-length-array
 
 // <type_traits>
 

From db95d1d2c59130f98235ebd22cc0c206baf58c62 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Thu, 5 Sep 2024 18:04:51 +0300
Subject: [PATCH 05/13] Addressed philnik's comment

---
 .../meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp  | 2 +-
 .../meta.unary.prop/is_implicit_lifetime.verify.cpp           | 4 +---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 8052fcb64a54b..cf85280535813 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -9,7 +9,7 @@
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
 // These compilers don't support __builtin_is_implicit_lifetime yet.
-// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-15, apple-clang-16, apple-clang-17
+// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-15, apple-clang-16
 
 // <type_traits>
 
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
index 657d84c5bc9da..516ab21888572 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
@@ -9,9 +9,7 @@
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
 // These compilers don't support __builtin_is_implicit_lifetime yet.
-// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-15, apple-clang-16, apple-clang-17
-
-// ADDITIONAL_COMPILE_FLAGS: -Wno-vla, -Wno-zero-length-array
+// UNSUPPORTED: clang-17, clang-18, clang-19, gcc-14, apple-clang-15, apple-clang-16
 
 // <type_traits>
 

From 69ac1d35cc8279261b83ec7610db179fbae3c32c Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Sun, 8 Sep 2024 18:05:03 +0300
Subject: [PATCH 06/13] Addressed some comments

---
 .../meta.unary.prop/is_implicit_lifetime.pass.cpp          | 7 -------
 .../meta.unary.prop/is_implicit_lifetime.verify.cpp        | 6 ------
 2 files changed, 13 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index cf85280535813..bfcb5c4b51f3f 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -139,7 +139,6 @@ constexpr void test_is_implicit_lifetime() {
 constexpr bool test() {
   // Standard fundamental C++ types
 
-  test_is_implicit_lifetime<decltype(nullptr), true>();
   test_is_implicit_lifetime<std::nullptr_t, true>();
 
   test_is_implicit_lifetime<void, false>();
@@ -255,12 +254,6 @@ constexpr bool test() {
   test_is_implicit_lifetime<std::pair<int, float>>();
   test_is_implicit_lifetime<std::tuple<int, float>>();
 
-  // Standard C types
-
-  test_is_implicit_lifetime<_Complex float>();
-  test_is_implicit_lifetime<_Complex double>();
-  test_is_implicit_lifetime<_Complex long double>();
-
   // Standard C23 types
 
 #ifdef TEST_COMPILER_CLANG
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
index 516ab21888572..25bba30da612e 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.verify.cpp
@@ -24,9 +24,3 @@ static_assert(!std::is_implicit_lifetime<IncompleteStruct>::value);
 
 // expected-error@*:* {{incomplete type 'IncompleteStruct' used in type trait expression}}
 static_assert(!std::is_implicit_lifetime_v<IncompleteStruct>);
-
-// expected-error@*:* {{atomic types are not supported in '__builtin_is_implicit_lifetime'}}
-static_assert(!std::is_implicit_lifetime<_Atomic int>::value);
-
-// expected-error@*:* {{atomic types are not supported in '__builtin_is_implicit_lifetime'}}
-static_assert(!std::is_implicit_lifetime_v<_Atomic int>);

From bf677ffc7ffd72b04f536092ac699b858a37dcb2 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Sun, 8 Sep 2024 18:06:35 +0300
Subject: [PATCH 07/13] Addressed more comments

---
 .../meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp     | 1 -
 1 file changed, 1 deletion(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index bfcb5c4b51f3f..65fd3cf02004e 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -129,7 +129,6 @@ constexpr void test_is_implicit_lifetime() {
 
   // Pointer types
   test_is_implicit_lifetime<T*, true>();
-  test_is_implicit_lifetime<T* __restrict, true>();
 
   // Arrays
   test_is_implicit_lifetime<T[], true>();

From dab49b84c9b92cc0ba8f753577a73b83bc4c9d4f Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Mon, 7 Oct 2024 08:02:08 +0300
Subject: [PATCH 08/13] Used `types::for_each` in tests

---
 .../is_implicit_lifetime.pass.cpp             | 32 ++++++-------------
 1 file changed, 9 insertions(+), 23 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 65fd3cf02004e..806bdf5aef08e 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -22,6 +22,7 @@
 #include <utility>
 
 #include "test_macros.h"
+#include "type_algorithms.h"
 
 enum Enum { EV };
 enum SignedEnum : signed int {};
@@ -135,6 +136,13 @@ constexpr void test_is_implicit_lifetime() {
   test_is_implicit_lifetime<T[94], true>();
 }
 
+struct AritmeticTypesTest {
+  template <class T>
+  constexpr void operator()() {
+    test_is_implicit_lifetime<T>();
+  }
+};
+
 constexpr bool test() {
   // Standard fundamental C++ types
 
@@ -160,29 +168,7 @@ constexpr bool test() {
   test_is_implicit_lifetime<char16_t>();
   test_is_implicit_lifetime<char32_t>();
 
-  test_is_implicit_lifetime<short>();
-  test_is_implicit_lifetime<short int>();
-  test_is_implicit_lifetime<signed short>();
-  test_is_implicit_lifetime<signed short int>();
-  test_is_implicit_lifetime<unsigned short>();
-  test_is_implicit_lifetime<unsigned short int>();
-  test_is_implicit_lifetime<int>();
-  test_is_implicit_lifetime<signed>();
-  test_is_implicit_lifetime<signed int>();
-  test_is_implicit_lifetime<unsigned>();
-  test_is_implicit_lifetime<unsigned int>();
-  test_is_implicit_lifetime<long>();
-  test_is_implicit_lifetime<long int>();
-  test_is_implicit_lifetime<signed long>();
-  test_is_implicit_lifetime<signed long int>();
-  test_is_implicit_lifetime<unsigned long>();
-  test_is_implicit_lifetime<unsigned long int>();
-  test_is_implicit_lifetime<long long>();
-  test_is_implicit_lifetime<long long int>();
-  test_is_implicit_lifetime<signed long long>();
-  test_is_implicit_lifetime<signed long long int>();
-  test_is_implicit_lifetime<unsigned long long>();
-  test_is_implicit_lifetime<unsigned long long int>();
+  types::for_each(types::arithmetic_types(), AritmeticTypesTest{});
 
   test_is_implicit_lifetime<float>();
   test_is_implicit_lifetime<double>();

From a4c4bcaf8c0d6c686d1a02c29cd1a418ad88036d Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Mon, 7 Oct 2024 08:38:57 +0300
Subject: [PATCH 09/13] Fixed `module.modulemap`

---
 libcxx/include/module.modulemap | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
index dee9b0b88b794..bb119722c5545 100644
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -200,6 +200,10 @@ module std_core [system] {
       header "__type_traits/is_fundamental.h"
       export std_core.type_traits.integral_constant
     }
+    module is_implicit_lifetime {
+      header "__type_traits/is_implicit_lifetime.h"
+      export std_core.type_traits.is_implicit_lifetime
+    }
     module is_implicitly_default_constructible {
       header "__type_traits/is_implicitly_default_constructible.h"
       export std_core.type_traits.integral_constant

From 11f94896aa3405e4116c7cea114d06672f3a3e7f Mon Sep 17 00:00:00 2001
From: Hristo Hristov <zingam@outlook.com>
Date: Mon, 7 Oct 2024 08:46:34 +0300
Subject: [PATCH 10/13] Update libcxx/docs/ReleaseNotes/20.rst

---
 libcxx/docs/ReleaseNotes/20.rst | 1 -
 1 file changed, 1 deletion(-)

diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
index 85060fdbe51ca..dcb1102d81d64 100644
--- a/libcxx/docs/ReleaseNotes/20.rst
+++ b/libcxx/docs/ReleaseNotes/20.rst
@@ -44,7 +44,6 @@ Implemented Papers
 - ``std::jthread`` and ``<stop_token>`` are not guarded behind ``-fexperimental-library`` anymore
 - P2674R1: A trait for implicit lifetime types (`Github <https://github.com/llvm/llvm-project/issues/105259>`__)
 
-
 Improvements and New Features
 -----------------------------
 

From 2b478fb20aab347f06d9ae6ab76a43c879ddfd60 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Tue, 8 Oct 2024 07:15:15 +0300
Subject: [PATCH 11/13] Test atomic

---
 .../is_implicit_lifetime.pass.cpp             | 27 +++++--------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 806bdf5aef08e..6eab6a4e01414 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -15,6 +15,7 @@
 
 // template<class T> struct is_implicit_lifetime;
 
+#include <atomic>
 #include <cassert>
 #include <cstddef>
 #include <tuple>
@@ -134,6 +135,12 @@ constexpr void test_is_implicit_lifetime() {
   // Arrays
   test_is_implicit_lifetime<T[], true>();
   test_is_implicit_lifetime<T[94], true>();
+
+  if !consteval {
+    if constexpr (std::is_trivially_copyable_v<T>) {
+      test_is_implicit_lifetime<std::atomic<T>, true>();
+    }
+  }
 }
 
 struct AritmeticTypesTest {
@@ -152,28 +159,8 @@ constexpr bool test() {
   test_is_implicit_lifetime<const void, false>();
   test_is_implicit_lifetime<volatile void, false>();
 
-  test_is_implicit_lifetime<bool>();
-
-  test_is_implicit_lifetime<char>();
-  test_is_implicit_lifetime<signed char>();
-  test_is_implicit_lifetime<unsigned char>();
-
-#if !defined(TEST_HAS_NO_WIDE_CHARACTERS)
-  test_is_implicit_lifetime<wchar_t>();
-#endif
-
-#if !defined(TEST_HAS_NO_CHAR8_T)
-  test_is_implicit_lifetime<char8_t>();
-#endif
-  test_is_implicit_lifetime<char16_t>();
-  test_is_implicit_lifetime<char32_t>();
-
   types::for_each(types::arithmetic_types(), AritmeticTypesTest{});
 
-  test_is_implicit_lifetime<float>();
-  test_is_implicit_lifetime<double>();
-  test_is_implicit_lifetime<long double>();
-
   test_is_implicit_lifetime<Enum>();
   test_is_implicit_lifetime<SignedEnum>();
   test_is_implicit_lifetime<UnsignedEnum>();

From 647b10a0269b22cb7dc5e2976d5b97c532e3e57a Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Tue, 8 Oct 2024 07:17:20 +0300
Subject: [PATCH 12/13] Cleanup

---
 .../meta.unary.prop/is_implicit_lifetime.pass.cpp          | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 6eab6a4e01414..a6ab77158aae1 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -15,7 +15,6 @@
 
 // template<class T> struct is_implicit_lifetime;
 
-#include <atomic>
 #include <cassert>
 #include <cstddef>
 #include <tuple>
@@ -135,12 +134,6 @@ constexpr void test_is_implicit_lifetime() {
   // Arrays
   test_is_implicit_lifetime<T[], true>();
   test_is_implicit_lifetime<T[94], true>();
-
-  if !consteval {
-    if constexpr (std::is_trivially_copyable_v<T>) {
-      test_is_implicit_lifetime<std::atomic<T>, true>();
-    }
-  }
 }
 
 struct AritmeticTypesTest {

From 13e4470fe2d52f4b726a02d80c7660241acc0374 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm@gmail.com>
Date: Tue, 8 Oct 2024 19:55:52 +0300
Subject: [PATCH 13/13] Addressed review comment

---
 libcxx/include/module.modulemap | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
index bb119722c5545..22a1313498e73 100644
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -202,7 +202,7 @@ module std_core [system] {
     }
     module is_implicit_lifetime {
       header "__type_traits/is_implicit_lifetime.h"
-      export std_core.type_traits.is_implicit_lifetime
+      export std_core.type_traits.integral_constant
     }
     module is_implicitly_default_constructible {
       header "__type_traits/is_implicitly_default_constructible.h"