//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <numeric>

// template <InputIterator InIter,
//           OutputIterator<auto, const InIter::value_type&> OutIter,
//           Callable<auto, const InIter::value_type&, const InIter::value_type&> BinaryOperation>
//   requires Constructible<InIter::value_type, InIter::reference>
//         && OutputIterator<OutIter, BinaryOperation::result_type>
//         && MoveAssignable<InIter::value_type>
//         && CopyConstructible<BinaryOperation>
//   OutIter
//   adjacent_difference(InIter first, InIter last, OutIter result, BinaryOperation binary_op);

#include <numeric>
#include <functional>
#include <cassert>

#include "test_iterators.h"

template <class InIter, class OutIter>
void
test()
{
    int ia[] = {15, 10, 6, 3, 1};
    int ir[] = {15, 25, 16, 9, 4};
    const unsigned s = sizeof(ia) / sizeof(ia[0]);
    int ib[s] = {0};
    OutIter r = std::adjacent_difference(InIter(ia), InIter(ia+s), OutIter(ib),
                                         std::plus<int>());
    assert(base(r) == ib + s);
    for (unsigned i = 0; i < s; ++i)
        assert(ib[i] == ir[i]);
}

int main()
{
    test<input_iterator<const int*>, output_iterator<int*> >();
    test<input_iterator<const int*>, forward_iterator<int*> >();
    test<input_iterator<const int*>, bidirectional_iterator<int*> >();
    test<input_iterator<const int*>, random_access_iterator<int*> >();
    test<input_iterator<const int*>, int*>();

    test<forward_iterator<const int*>, output_iterator<int*> >();
    test<forward_iterator<const int*>, forward_iterator<int*> >();
    test<forward_iterator<const int*>, bidirectional_iterator<int*> >();
    test<forward_iterator<const int*>, random_access_iterator<int*> >();
    test<forward_iterator<const int*>, int*>();

    test<bidirectional_iterator<const int*>, output_iterator<int*> >();
    test<bidirectional_iterator<const int*>, forward_iterator<int*> >();
    test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
    test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
    test<bidirectional_iterator<const int*>, int*>();

    test<random_access_iterator<const int*>, output_iterator<int*> >();
    test<random_access_iterator<const int*>, forward_iterator<int*> >();
    test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
    test<random_access_iterator<const int*>, random_access_iterator<int*> >();
    test<random_access_iterator<const int*>, int*>();

    test<const int*, output_iterator<int*> >();
    test<const int*, forward_iterator<int*> >();
    test<const int*, bidirectional_iterator<int*> >();
    test<const int*, random_access_iterator<int*> >();
    test<const int*, int*>();
}