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