__cxx03/__atomic/is_always_lock_free.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___CXX03___ATOMIC_IS_ALWAYS_LOCK_FREE_H
0010 #define _LIBCPP___CXX03___ATOMIC_IS_ALWAYS_LOCK_FREE_H
0011
0012 #include <__cxx03/__config>
0013
0014 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0015 #  pragma GCC system_header
0016 #endif
0017
0018 _LIBCPP_BEGIN_NAMESPACE_STD
0019
0020 template <class _Tp>
0021 struct __libcpp_is_always_lock_free {
0022   // __atomic_always_lock_free is available in all Standard modes
0023   static const bool __value = __atomic_always_lock_free(sizeof(_Tp), nullptr);
0024 };
0025
0026 _LIBCPP_END_NAMESPACE_STD
0027
0028 #endif // _LIBCPP___CXX03___ATOMIC_IS_ALWAYS_LOCK_FREE_H