176d0caaeSpatrick //===----------------------------------------------------------------------===// 276d0caaeSpatrick // 376d0caaeSpatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 476d0caaeSpatrick // See https://llvm.org/LICENSE.txt for license information. 576d0caaeSpatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 676d0caaeSpatrick // 776d0caaeSpatrick //===----------------------------------------------------------------------===// 876d0caaeSpatrick 976d0caaeSpatrick #ifndef _LIBCPP___UTILITY_EXCHANGE_H 1076d0caaeSpatrick #define _LIBCPP___UTILITY_EXCHANGE_H 1176d0caaeSpatrick 1276d0caaeSpatrick #include <__config> 13*4bdff4beSrobert #include <__type_traits/is_nothrow_assignable.h> 14*4bdff4beSrobert #include <__type_traits/is_nothrow_move_constructible.h> 1576d0caaeSpatrick #include <__utility/forward.h> 1676d0caaeSpatrick #include <__utility/move.h> 1776d0caaeSpatrick 1876d0caaeSpatrick #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 1976d0caaeSpatrick # pragma GCC system_header 2076d0caaeSpatrick #endif 2176d0caaeSpatrick 2276d0caaeSpatrick _LIBCPP_BEGIN_NAMESPACE_STD 2376d0caaeSpatrick 2476d0caaeSpatrick #if _LIBCPP_STD_VER > 11 2576d0caaeSpatrick template<class _T1, class _T2 = _T1> 26*4bdff4beSrobert inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 exchange(_T1 & __obj,_T2 && __new_value)2776d0caaeSpatrick_T1 exchange(_T1& __obj, _T2&& __new_value) 28*4bdff4beSrobert noexcept(is_nothrow_move_constructible<_T1>::value && is_nothrow_assignable<_T1&, _T2>::value) 2976d0caaeSpatrick { 3076d0caaeSpatrick _T1 __old_value = _VSTD::move(__obj); 3176d0caaeSpatrick __obj = _VSTD::forward<_T2>(__new_value); 3276d0caaeSpatrick return __old_value; 3376d0caaeSpatrick } 3476d0caaeSpatrick #endif // _LIBCPP_STD_VER > 11 3576d0caaeSpatrick 3676d0caaeSpatrick _LIBCPP_END_NAMESPACE_STD 3776d0caaeSpatrick 3876d0caaeSpatrick #endif // _LIBCPP___UTILITY_EXCHANGE_H 39