xref: /freebsd-src/contrib/llvm-project/libcxx/include/__utility/swap.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
2fe6060f1SDimitry Andric //
3fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6fe6060f1SDimitry Andric //
7fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
8fe6060f1SDimitry Andric 
9fe6060f1SDimitry Andric #ifndef _LIBCPP___UTILITY_SWAP_H
10fe6060f1SDimitry Andric #define _LIBCPP___UTILITY_SWAP_H
11fe6060f1SDimitry Andric 
12fe6060f1SDimitry Andric #include <__config>
13*0fca6ea1SDimitry Andric #include <__type_traits/is_assignable.h>
14*0fca6ea1SDimitry Andric #include <__type_traits/is_constructible.h>
15*0fca6ea1SDimitry Andric #include <__type_traits/is_nothrow_assignable.h>
16*0fca6ea1SDimitry Andric #include <__type_traits/is_nothrow_constructible.h>
17bdd1243dSDimitry Andric #include <__type_traits/is_swappable.h>
18fe6060f1SDimitry Andric #include <__utility/declval.h>
19fe6060f1SDimitry Andric #include <__utility/move.h>
20fe6060f1SDimitry Andric #include <cstddef>
21fe6060f1SDimitry Andric 
22fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23fe6060f1SDimitry Andric #  pragma GCC system_header
24fe6060f1SDimitry Andric #endif
25fe6060f1SDimitry Andric 
2606c3fb27SDimitry Andric _LIBCPP_PUSH_MACROS
2706c3fb27SDimitry Andric #include <__undef_macros>
2806c3fb27SDimitry Andric 
29fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
30fe6060f1SDimitry Andric 
31fe6060f1SDimitry Andric #ifndef _LIBCPP_CXX03_LANG
32fe6060f1SDimitry Andric template <class _Tp>
335f757f3fSDimitry Andric using __swap_result_t = __enable_if_t<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>;
34fe6060f1SDimitry Andric #else
35fe6060f1SDimitry Andric template <class>
36fe6060f1SDimitry Andric using __swap_result_t = void;
37fe6060f1SDimitry Andric #endif
38fe6060f1SDimitry Andric 
39fe6060f1SDimitry Andric template <class _Tp>
405f757f3fSDimitry Andric inline _LIBCPP_HIDE_FROM_ABI __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_SINCE_CXX20 swap(_Tp& __x, _Tp& __y)
41fe6060f1SDimitry Andric     _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value&& is_nothrow_move_assignable<_Tp>::value) {
425f757f3fSDimitry Andric   _Tp __t(std::move(__x));
435f757f3fSDimitry Andric   __x = std::move(__y);
445f757f3fSDimitry Andric   __y = std::move(__t);
45fe6060f1SDimitry Andric }
46fe6060f1SDimitry Andric 
47*0fca6ea1SDimitry Andric template <class _Tp, size_t _Np, __enable_if_t<__is_swappable_v<_Tp>, int> >
485f757f3fSDimitry Andric inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np])
49*0fca6ea1SDimitry Andric     _NOEXCEPT_(__is_nothrow_swappable_v<_Tp>) {
50fe6060f1SDimitry Andric   for (size_t __i = 0; __i != _Np; ++__i) {
51fe6060f1SDimitry Andric     swap(__a[__i], __b[__i]);
52fe6060f1SDimitry Andric   }
53fe6060f1SDimitry Andric }
54fe6060f1SDimitry Andric 
55fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
56fe6060f1SDimitry Andric 
5706c3fb27SDimitry Andric _LIBCPP_POP_MACROS
5806c3fb27SDimitry Andric 
59fe6060f1SDimitry Andric #endif // _LIBCPP___UTILITY_SWAP_H
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