is_referenceable.h revision 1.1.1.1
1//===----------------------------------------------------------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8 9#ifndef _LIBCPP___TYPE_TRAITS_IS_REFERENCEABLE_H 10#define _LIBCPP___TYPE_TRAITS_IS_REFERENCEABLE_H 11 12#include <__config> 13#include <__type_traits/integral_constant.h> 14#include <__type_traits/is_same.h> 15 16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17# pragma GCC system_header 18#endif 19 20_LIBCPP_BEGIN_NAMESPACE_STD 21 22#if __has_builtin(__is_referenceable) 23template <class _Tp> 24struct __libcpp_is_referenceable : integral_constant<bool, __is_referenceable(_Tp)> {}; 25#else 26struct __libcpp_is_referenceable_impl { 27 template <class _Tp> 28 static _Tp& __test(int); 29 template <class _Tp> 30 static false_type __test(...); 31}; 32 33template <class _Tp> 34struct __libcpp_is_referenceable 35 : integral_constant<bool, _IsNotSame<decltype(__libcpp_is_referenceable_impl::__test<_Tp>(0)), false_type>::value> { 36}; 37#endif // __has_builtin(__is_referenceable) 38 39_LIBCPP_END_NAMESPACE_STD 40 41#endif // _LIBCPP___TYPE_TRAITS_IS_REFERENCEABLE_H 42