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