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_ALIGNED_UNION_H 10#define _LIBCPP___TYPE_TRAITS_ALIGNED_UNION_H 11 12#include <__config> 13#include <__type_traits/aligned_storage.h> 14#include <__type_traits/integral_constant.h> 15#include <cstddef> 16 17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18# pragma GCC system_header 19#endif 20 21_LIBCPP_BEGIN_NAMESPACE_STD 22 23template <size_t _I0, size_t... _In> 24struct __static_max; 25 26template <size_t _I0> 27struct __static_max<_I0> { 28 static const size_t value = _I0; 29}; 30 31template <size_t _I0, size_t _I1, size_t... _In> 32struct __static_max<_I0, _I1, _In...> { 33 static const size_t value = _I0 >= _I1 ? __static_max<_I0, _In...>::value : __static_max<_I1, _In...>::value; 34}; 35 36template <size_t _Len, class _Type0, class... _Types> 37struct _LIBCPP_DEPRECATED_IN_CXX23 aligned_union { 38 static const size_t alignment_value = 39 __static_max<_LIBCPP_PREFERRED_ALIGNOF(_Type0), _LIBCPP_PREFERRED_ALIGNOF(_Types)...>::value; 40 static const size_t __len = __static_max<_Len, sizeof(_Type0), sizeof(_Types)...>::value; 41 typedef typename aligned_storage<__len, alignment_value>::type type; 42}; 43 44#if _LIBCPP_STD_VER >= 14 45template <size_t _Len, class... _Types> 46using aligned_union_t _LIBCPP_DEPRECATED_IN_CXX23 = typename aligned_union<_Len, _Types...>::type; 47#endif 48 49_LIBCPP_END_NAMESPACE_STD 50 51#endif // _LIBCPP___TYPE_TRAITS_ALIGNED_UNION_H 52