//===----------------------------------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//

// <functional>
//
// template <class T>
// struct unwrap_ref_decay;
//
// template <class T>
// using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type;

// UNSUPPORTED: c++17

// #include <cuda/std/functional>
#include <cuda/std/type_traits>
#include <cuda/std/utility>

#include "test_macros.h"

template <typename T, typename Result>
__host__ __device__ void check()
{
  static_assert(cuda::std::is_same_v<typename cuda::std::unwrap_ref_decay<T>::type, Result>);
  static_assert(cuda::std::is_same_v<typename cuda::std::unwrap_ref_decay<T>::type, cuda::std::unwrap_ref_decay_t<T>>);
}

struct T
{};

int main(int, char**)
{
  check<T, T>();
  check<T&, T>();
  check<T const, T>();
  check<T const&, T>();
  check<T*, T*>();
  check<T const*, T const*>();
  check<T[3], T*>();
  check<T const[3], T const*>();
  check<T(), T (*)()>();
  check<T(int) const, T(int) const>();
  check<T(int)&, T(int)&>();
  check<T(int)&&, T(int) &&>();

  check<cuda::std::reference_wrapper<T>, T&>();
  check<cuda::std::reference_wrapper<T>&, T&>();
  check<cuda::std::reference_wrapper<T const>, T const&>();
  check<cuda::std::reference_wrapper<T const>&, T const&>();
  check<cuda::std::reference_wrapper<T*>, T*&>();
  check<cuda::std::reference_wrapper<T*>&, T*&>();
  check<cuda::std::reference_wrapper<T const*>, T const*&>();
  check<cuda::std::reference_wrapper<T const*>&, T const*&>();
  check<cuda::std::reference_wrapper<T[3]>, T(&)[3]>();
  check<cuda::std::reference_wrapper<T[3]>&, T(&)[3]>();
  check<cuda::std::reference_wrapper<T()>, T (&)()>();
  check<cuda::std::reference_wrapper<T()>&, T (&)()>();

  return 0;
}
