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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___UTILITY_EXCHANGE_H
#define _LIBCPP___UTILITY_EXCHANGE_H
#include <__config>
#include <__utility/forward.h>
#include <__utility/move.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 11
template<class _T1, class _T2 = _T1>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
_T1 exchange(_T1& __obj, _T2&& __new_value)
noexcept(is_nothrow_move_constructible<_T1>::value && is_nothrow_assignable<_T1&, _T2>::value)
{
_T1 __old_value = _VSTD::move(__obj);
__obj = _VSTD::forward<_T2>(__new_value);
return __old_value;
}
#endif // _LIBCPP_STD_VER > 11
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___UTILITY_EXCHANGE_H
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