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

// <array>

// reference at (size_type); // constexpr in C++17

#include <array>
#include <cassert>

#ifndef TEST_HAS_NO_EXCEPTIONS
#  include <stdexcept>
#endif

#include "test_macros.h"

TEST_CONSTEXPR_CXX17 bool tests() {
  {
    typedef double T;
    typedef std::array<T, 3> C;
    C c                      = {1, 2, 3.5};
    typename C::reference r1 = c.at(0);
    assert(r1 == 1);
    r1 = 5.5;
    assert(c[0] == 5.5);

    typename C::reference r2 = c.at(2);
    assert(r2 == 3.5);
    r2 = 7.5;
    assert(c[2] == 7.5);
  }
  return true;
}

void test_exceptions() {
#ifndef TEST_HAS_NO_EXCEPTIONS
  {
    std::array<int, 4> array = {1, 2, 3, 4};

    try {
      TEST_IGNORE_NODISCARD array.at(4);
      assert(false);
    } catch (std::out_of_range const&) {
      // pass
    } catch (...) {
      assert(false);
    }

    try {
      TEST_IGNORE_NODISCARD array.at(5);
      assert(false);
    } catch (std::out_of_range const&) {
      // pass
    } catch (...) {
      assert(false);
    }

    try {
      TEST_IGNORE_NODISCARD array.at(6);
      assert(false);
    } catch (std::out_of_range const&) {
      // pass
    } catch (...) {
      assert(false);
    }

    try {
      using size_type = decltype(array)::size_type;
      TEST_IGNORE_NODISCARD array.at(static_cast<size_type>(-1));
      assert(false);
    } catch (std::out_of_range const&) {
      // pass
    } catch (...) {
      assert(false);
    }
  }

  {
    std::array<int, 0> array = {};

    try {
      TEST_IGNORE_NODISCARD array.at(0);
      assert(false);
    } catch (std::out_of_range const&) {
      // pass
    } catch (...) {
      assert(false);
    }
  }
#endif
}

int main(int, char**) {
  tests();
  test_exceptions();

#if TEST_STD_VER >= 17
  static_assert(tests(), "");
#endif
  return 0;
}