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

// <cuda/std/iterator>

// reverse_iterator

// requires RandomAccessIterator<Iter>
// unspecified operator[](difference_type n) const; // constexpr since C++17

#include <cuda/std/cassert>
#include <cuda/std/iterator>

#include "test_iterators.h"
#include "test_macros.h"

template <class It>
__host__ __device__ constexpr void
test(It i,
     typename cuda::std::iterator_traits<It>::difference_type n,
     typename cuda::std::iterator_traits<It>::value_type x)
{
  typedef typename cuda::std::iterator_traits<It>::value_type value_type;
  const cuda::std::reverse_iterator<It> r(i);
  value_type rr = r[n];
  assert(rr == x);
}

__host__ __device__ constexpr bool tests()
{
  const char* s = "1234567890";
  test(random_access_iterator<const char*>(s + 5), 4, '1');
  test(random_access_iterator<const char*>(s + 5), 0, '5');
  test(s + 5, 4, '1');
  test(s + 5, 0, '5');
  return true;
}

int main(int, char**)
{
  tests();
  static_assert(tests(), "");
  return 0;
}
