//===----------------------------------------------------------------------===//
//
// 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
// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCUDACXX___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H
#define _LIBCUDACXX___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H

#include <cuda/std/detail/__config>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#include <cuda/std/__type_traits/is_referenceable.h>

_LIBCUDACXX_BEGIN_NAMESPACE_STD

#if defined(_CCCL_BUILTIN_ADD_LVALUE_REFERENCE) && !defined(_LIBCUDACXX_USE_ADD_LVALUE_REFERENCE_FALLBACK)

template <class _Tp>
using add_lvalue_reference_t _CCCL_NODEBUG_ALIAS = _CCCL_BUILTIN_ADD_LVALUE_REFERENCE(_Tp);

#else // ^^^ _CCCL_BUILTIN_ADD_LVALUE_REFERENCE ^^^ / vvv !_CCCL_BUILTIN_ADD_LVALUE_REFERENCE vvv

template <class _Tp, bool = __cccl_is_referenceable<_Tp>::value>
struct __add_lvalue_reference_impl
{
  using type _CCCL_NODEBUG_ALIAS = _Tp;
};
template <class _Tp>
struct __add_lvalue_reference_impl<_Tp, true>
{
  using type _CCCL_NODEBUG_ALIAS = _Tp&;
};

template <class _Tp>
using add_lvalue_reference_t _CCCL_NODEBUG_ALIAS = typename __add_lvalue_reference_impl<_Tp>::type;

#endif // !_CCCL_BUILTIN_ADD_LVALUE_REFERENCE

template <class _Tp>
struct add_lvalue_reference
{
  using type _CCCL_NODEBUG_ALIAS = add_lvalue_reference_t<_Tp>;
};

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H
