xref: /external/libcxx/test/iterators/predef.iterators/reverse.iterators/reverse.iter.ops/reverse.iter.op-/difference_type.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <iterator>

// reverse_iterator

// requires RandomAccessIterator<Iter>
//   reverse_iterator operator-(difference_type n) const;

#include <iterator>
#include <cassert>

#include "../../../../iterators.h"

template <class It>
void
test(It i, typename std::iterator_traits<It>::difference_type n, It x)
{
    const std::reverse_iterator<It> r(i);
    std::reverse_iterator<It> rr = r - n;
    assert(rr.base() == x);
}

int main()
{
    const char* s = "1234567890";
    test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10));
    test(s+5, 5, s+10);
}