1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <iterator>
11
12// template <BidirectionalIterator Iter>
13//   Iter prev(Iter x, Iter::difference_type n = 1);
14
15#include <iterator>
16#include <cassert>
17
18#include "test_iterators.h"
19
20template <class It>
21void
22test(It i, typename std::iterator_traits<It>::difference_type n, It x)
23{
24    assert(std::prev(i, n) == x);
25}
26
27template <class It>
28void
29test(It i, It x)
30{
31    assert(std::prev(i) == x);
32}
33
34int main()
35{
36    const char* s = "1234567890";
37    test(bidirectional_iterator<const char*>(s+10), 10, bidirectional_iterator<const char*>(s));
38    test(random_access_iterator<const char*>(s+10), 10, random_access_iterator<const char*>(s));
39    test(s+10, 10, s);
40
41    test(bidirectional_iterator<const char*>(s+1), bidirectional_iterator<const char*>(s));
42    test(random_access_iterator<const char*>(s+1), random_access_iterator<const char*>(s));
43    test(s+1, s);
44}
45