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 <__cstddef/size_t.h>
14#include <__type_traits/enable_if.h>
15#include <__type_traits/is_assignable.h>
16#include <__type_traits/is_constructible.h>
17#include <__type_traits/is_nothrow_assignable.h>
18#include <__type_traits/is_nothrow_constructible.h>
19#include <__type_traits/is_swappable.h>
20#include <__utility/move.h>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23#  pragma GCC system_header
24#endif
25
26_LIBCPP_PUSH_MACROS
27#include <__undef_macros>
28
29_LIBCPP_BEGIN_NAMESPACE_STD
30
31#ifndef _LIBCPP_CXX03_LANG
32template <class _Tp>
33using __swap_result_t _LIBCPP_NODEBUG =
34    __enable_if_t<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>;
35#else
36template <class>
37using __swap_result_t _LIBCPP_NODEBUG = void;
38#endif
39
40template <class _Tp>
41inline _LIBCPP_HIDE_FROM_ABI __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_SINCE_CXX20 swap(_Tp& __x, _Tp& __y)
42    _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value&& is_nothrow_move_assignable<_Tp>::value) {
43  _Tp __t(std::move(__x));
44  __x = std::move(__y);
45  __y = std::move(__t);
46}
47
48template <class _Tp, size_t _Np, __enable_if_t<__is_swappable_v<_Tp>, int> >
49inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np])
50    _NOEXCEPT_(__is_nothrow_swappable_v<_Tp>) {
51  for (size_t __i = 0; __i != _Np; ++__i) {
52    swap(__a[__i], __b[__i]);
53  }
54}
55
56_LIBCPP_END_NAMESPACE_STD
57
58_LIBCPP_POP_MACROS
59
60#endif // _LIBCPP___UTILITY_SWAP_H