zig/lib/libcxx/include/__utility/exchange.h
Andrew Kelley 5d4439cc3e libcxx: update to LLVM 17
release/17.x branch, commit 8f4dd44097c9ae25dd203d5ac87f3b48f854bba8

This adds the flag `-D_LIBCPP_PSTL_CPU_BACKEND_SERIAL`. A future
enhancement could possibly pass something different if there is a
compelling parallel implementation. That libdispatch one might be worth
looking into.
2023-09-19 09:37:31 -07:00

43 lines
1.3 KiB
C++
Vendored

//===----------------------------------------------------------------------===//
//
// 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 <__type_traits/is_nothrow_assignable.h>
#include <__type_traits/is_nothrow_move_constructible.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 14
template<class _T1, class _T2 = _T1>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
_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 >= 14
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___UTILITY_EXCHANGE_H