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41 lines
1.3 KiB
C++
41 lines
1.3 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___UTILITY_EXCHANGE_H
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#define _LIBCPP___UTILITY_EXCHANGE_H
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#include <__config>
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#include <__type_traits/is_nothrow_assignable.h>
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#include <__type_traits/is_nothrow_constructible.h>
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#include <__utility/forward.h>
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#include <__utility/move.h>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_PUSH_MACROS
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#include <__undef_macros>
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_LIBCPP_BEGIN_NAMESPACE_STD
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#if _LIBCPP_STD_VER >= 14
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template <class _T1, class _T2 = _T1>
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inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _T1 exchange(_T1& __obj, _T2&& __new_value) noexcept(
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is_nothrow_move_constructible<_T1>::value && is_nothrow_assignable<_T1&, _T2>::value) {
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_T1 __old_value = std::move(__obj);
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__obj = std::forward<_T2>(__new_value);
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return __old_value;
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}
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#endif // _LIBCPP_STD_VER >= 14
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_LIBCPP_END_NAMESPACE_STD
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_LIBCPP_POP_MACROS
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#endif // _LIBCPP___UTILITY_EXCHANGE_H
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