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 // template <RandomAccessIterator Iterator>
15 // constexpr reverse_iterator<Iter>
16 // operator+(Iter::difference_type n, const reverse_iterator<Iter>& x);
17 //
18 // constexpr in C++17
19
20 #include <iterator>
21 #include <cassert>
22
23 #include "test_macros.h"
24 #include "test_iterators.h"
25
26 template <class It>
27 void
test(It i,typename std::iterator_traits<It>::difference_type n,It x)28 test(It i, typename std::iterator_traits<It>::difference_type n, It x)
29 {
30 const std::reverse_iterator<It> r(i);
31 std::reverse_iterator<It> rr = n + r;
32 assert(rr.base() == x);
33 }
34
main()35 int main()
36 {
37 const char* s = "1234567890";
38 test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s));
39 test(s+5, 5, s);
40
41 #if TEST_STD_VER > 14
42 {
43 constexpr const char *p = "123456789";
44 typedef std::reverse_iterator<const char *> RI;
45 constexpr RI it1 = std::make_reverse_iterator(p);
46 constexpr RI it2 = std::make_reverse_iterator(p + 5);
47 constexpr RI it3 = 5 + it2;
48 static_assert(it1 != it2, "");
49 static_assert(it1 == it3, "");
50 static_assert(it2 != it3, "");
51 }
52 #endif
53 }
54