//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

// <cuda/std/functional>

// minus

#define _LIBCUDACXX_DISABLE_DEPRECATION_WARNINGS

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

#include "test_macros.h"

// ensure that we allow `__device__` functions too
struct with_device_op
{
  __device__ friend constexpr with_device_op operator-(const with_device_op&, const with_device_op&)
  {
    return {};
  }
  __device__ constexpr operator bool() const
  {
    return true;
  }
};

__global__ void test_global_kernel()
{
  const cuda::std::minus<with_device_op> f;
  assert(f({}, {}));
}

int main(int, char**)
{
  typedef cuda::std::minus<int> F;
  const F f = F();
#if TEST_STD_VER <= 2017
  static_assert((cuda::std::is_same<int, F::first_argument_type>::value), "");
  static_assert((cuda::std::is_same<int, F::second_argument_type>::value), "");
  static_assert((cuda::std::is_same<int, F::result_type>::value), "");
#endif // TEST_STD_VER <= 2017
  assert(f(3, 2) == 1);

  typedef cuda::std::minus<> F2;
  const F2 f2 = F2();
  assert(f2(3, 2) == 1);
  assert(f2(3.0, 2) == 1);
  assert(f2(3, 2.5) == 0.5);
  constexpr int foo = cuda::std::minus<int>()(3, 2);
  static_assert(foo == 1, "");

  constexpr double bar = cuda::std::minus<>()(3.0, 2);
  static_assert(bar == 1.0, "");

  return 0;
}