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 29 template <class _Tp> 30 using __swap_result_t = typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type; 31 #else 32 template <class> 33 using __swap_result_t = void; 34 #endif 35 36 template <class _Tp> 37 inline _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 44 template <class _Tp, size_t _Np> 45 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 typename enable_if<__is_swappable<_Tp>::value>::type 46 swap(_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