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 // reverse_iterator
13
14 // requires RandomAccessIterator<Iter>
15 // unspecified operator[](difference_type n) const;
16
17 #include <iterator>
18 #include <cassert>
19
20 #include "test_macros.h"
21 #include "test_iterators.h"
22
23 template <class It>
24 void
test(It i,typename std::iterator_traits<It>::difference_type n,typename std::iterator_traits<It>::value_type x)25 test(It i, typename std::iterator_traits<It>::difference_type n,
26 typename std::iterator_traits<It>::value_type x)
27 {
28 typedef typename std::iterator_traits<It>::value_type value_type;
29 const std::reverse_iterator<It> r(i);
30 value_type rr = r[n];
31 assert(rr == x);
32 }
33
main()34 int main()
35 {
36 const char* s = "1234567890";
37 test(random_access_iterator<const char*>(s+5), 4, '1');
38 test(s+5, 4, '1');
39
40 #if TEST_STD_VER > 14
41 {
42 constexpr const char *p = "123456789";
43 typedef std::reverse_iterator<const char *> RI;
44 constexpr RI it1 = std::make_reverse_iterator(p + 5);
45 static_assert(it1[0] == '5', "");
46 static_assert(it1[4] == '1', "");
47 }
48 #endif
49 }
50