llvm/libcxx/include/__type_traits/has_unique_object_representation.h

//===----------------------------------------------------------------------===//
//
// 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_HAS_UNIQUE_OBJECT_REPRESENTATION_H
#define _LIBCPP___TYPE_TRAITS_HAS_UNIQUE_OBJECT_REPRESENTATION_H

#include <__config>
#include <__type_traits/integral_constant.h>
#include <__type_traits/remove_all_extents.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#if _LIBCPP_STD_VER >= 17

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS has_unique_object_representations
    // TODO: We work around a Clang and GCC bug in __has_unique_object_representations by using remove_all_extents
    //       even though it should not be necessary. This was reported to the compilers:
    //         - Clang: https://github.com/llvm/llvm-project/issues/95311
    //         - GCC: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115476
    //       remove_all_extents_t can be removed once all the compilers we support have fixed this bug.
    : public integral_constant<bool, __has_unique_object_representations(remove_all_extents_t<_Tp>)> {};

template <class _Tp>
inline constexpr bool has_unique_object_representations_v = __has_unique_object_representations(_Tp);

#endif

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___TYPE_TRAITS_HAS_UNIQUE_OBJECT_REPRESENTATION_H