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___UTILITY_SWAP_H
10#define _LIBCPP___UTILITY_SWAP_H
11
12#include <__config>
13#include <__type_traits/is_move_assignable.h>
14#include <__type_traits/is_move_constructible.h>
15#include <__type_traits/is_nothrow_move_assignable.h>
16#include <__type_traits/is_nothrow_move_constructible.h>
17#include <__type_traits/is_swappable.h>
18#include <__utility/declval.h>
19#include <__utility/move.h>
20#include <cstddef>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23#  pragma GCC system_header
24#endif
25
26_LIBCPP_BEGIN_NAMESPACE_STD
27
28#ifndef _LIBCPP_CXX03_LANG
29template <class _Tp>
30using __swap_result_t = typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type;
31#else
32template <class>
33using __swap_result_t = void;
34#endif
35
36template <class _Tp>
37inline _LIBCPP_INLINE_VISIBILITY __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_SINCE_CXX20 swap(_Tp& __x, _Tp& __y)
38    _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value&& is_nothrow_move_assignable<_Tp>::value) {
39  _Tp __t(_VSTD::move(__x));
40  __x = _VSTD::move(__y);
41  __y = _VSTD::move(__t);
42}
43
44template <class _Tp, size_t _Np>
45inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 typename enable_if<__is_swappable<_Tp>::value>::type
46swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
47  for (size_t __i = 0; __i != _Np; ++__i) {
48    swap(__a[__i], __b[__i]);
49  }
50}
51
52_LIBCPP_END_NAMESPACE_STD
53
54#endif // _LIBCPP___UTILITY_SWAP_H
55