1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___TYPE_TRAITS_HAS_UNIQUE_OBJECT_REPRESENTATION_H 10 #define _LIBCPP___TYPE_TRAITS_HAS_UNIQUE_OBJECT_REPRESENTATION_H 11 12 #include <__config> 13 #include <__type_traits/integral_constant.h> 14 #include <__type_traits/remove_all_extents.h> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 #if _LIBCPP_STD_VER >= 17 23 24 template <class _Tp> 25 struct _LIBCPP_TEMPLATE_VIS has_unique_object_representations 26 // TODO: We work around a Clang and GCC bug in __has_unique_object_representations by using remove_all_extents 27 // even though it should not be necessary. This was reported to the compilers: 28 // - Clang: https://github.com/llvm/llvm-project/issues/95311 29 // - GCC: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115476 30 // remove_all_extents_t can be removed once all the compilers we support have fixed this bug. 31 : public integral_constant<bool, __has_unique_object_representations(remove_all_extents_t<_Tp>)> {}; 32 33 template <class _Tp> 34 inline constexpr bool has_unique_object_representations_v = __has_unique_object_representations(_Tp); 35 36 #endif 37 38 _LIBCPP_END_NAMESPACE_STD 39 40 #endif // _LIBCPP___TYPE_TRAITS_HAS_UNIQUE_OBJECT_REPRESENTATION_H 41