post.pass.cpp revision 4414a6a91122ed02d42745e14ebefb116e5bf773 
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// constexpr reverse_iterator operator--(int);
15//
16// constexpr in C++17
17
18#include <iterator>
19#include <cassert>
20
21#include "test_macros.h"
22#include "test_iterators.h"
23
24template <class It>
25void
26test(It i, It x)
27{
28    std::reverse_iterator<It> r(i);
29    std::reverse_iterator<It> rr = r--;
30    assert(r.base() == x);
31    assert(rr.base() == i);
32}
33
34int main()
35{
36    const char* s = "123";
37    test(bidirectional_iterator<const char*>(s+1), bidirectional_iterator<const char*>(s+2));
38    test(random_access_iterator<const char*>(s+1), random_access_iterator<const char*>(s+2));
39    test(s+1, s+2);
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+1);
47        static_assert(it1 != it2, "");
48        constexpr RI it3 = std::make_reverse_iterator(p) --;
49        static_assert(it1 == it3, "");
50        static_assert(it2 != it3, "");
51    }
52#endif
53}
54