//===----------------------------------------------------------------------===//
//
// 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___TYPE_TRAITS_IS_REFERENCEABLE_H
#define _LIBCPP___TYPE_TRAITS_IS_REFERENCEABLE_H

#include <__config>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_same.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#if __has_builtin(__is_referenceable)
template <class _Tp>
struct __libcpp_is_referenceable : integral_constant<bool, __is_referenceable(_Tp)> {};
#else
struct __libcpp_is_referenceable_impl {
  template <class _Tp>
  static _Tp& __test(int);
  template <class _Tp>
  static false_type __test(...);
};

template <class _Tp>
struct __libcpp_is_referenceable
    : integral_constant<bool, _IsNotSame<decltype(__libcpp_is_referenceable_impl::__test<_Tp>(0)), false_type>::value> {
};
#endif // __has_builtin(__is_referenceable)

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___TYPE_TRAITS_IS_REFERENCEABLE_H