// Copyright (C) 2020-2023 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3.  If not see
// <http://www.gnu.org/licenses/>.

// { dg-options "-std=gnu++2a" }
// { dg-do run { target c++2a } }

#include <algorithm>
#include <testsuite_hooks.h>
#include <testsuite_iterators.h>
#include <list>

using __gnu_test::test_container;
using __gnu_test::test_range;
using __gnu_test::input_iterator_wrapper;
using __gnu_test::output_iterator_wrapper;
using __gnu_test::forward_iterator_wrapper;

namespace ranges = std::ranges;

struct X
{
  int i;
};

void
test01()
{
  const int c[6] = { 17, 17, 17, 4, 5, 6 };
    {
      X x[6] = { {1}, {2}, {3}, {4}, {5}, {6} };
      VERIFY( ranges::fill_n(x, 3, X{17}) == x+3 );
      VERIFY( ranges::equal(x, c, {}, &X::i) );
    }

    {
      char x[6];
      VERIFY( ranges::fill_n(x, 3, 17) == x+3 );
      VERIFY( ranges::equal(x, x+3, c, c+3) );
    }

    {
      X x[6] = { 1, 2, 3, 4, 5, 6 };
      test_container<X, forward_iterator_wrapper> cx(x);
      VERIFY( ranges::fill_n(cx.begin(), 3, X{17})->i == 4 );
      VERIFY( ranges::equal(cx, c, {}, &X::i) );
    }

    {
      int x[6] = { 1, 2, 3, 4, 5, 6 };;
      test_range<int, output_iterator_wrapper> rx(x);
      ranges::fill_n(ranges::begin(rx), 3, 17);
      VERIFY( ranges::equal(x, c) );
    }

    {
      std::list<int> list({1, 2, 3, 4, 5, 6});
      ranges::fill_n(list.begin(), 3, 17);
      VERIFY( ranges::equal(list, c) );
    }
}

template<typename T>
constexpr bool
test02()
{
  bool ok = true;
  T x[6] = { 1, 2, 3, 4, 5, 6 };
  const int y[6] = { 1, 2, 3, 4, 5, 6 };
  const int z[6] = { 17, 17, 17, 4, 5, 6 };

  ranges::fill_n(x, 0, 17);
  ranges::fill_n(x, -1, 17);
  ok &= ranges::equal(x, y);

  ranges::fill_n(x, 3, 17);
  ok &= ranges::equal(x, z);
  return ok;
}

int
main()
{
  test01();
  static_assert(test02<int>());
  static_assert(test02<unsigned char>()); // PR libstdc++/101608
}