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 // <string_view>
11 
12 // constexpr const_iterator rend() const;
13 
14 #include <experimental/string_view>
15 #include <cassert>
16 
17 template <class S>
18 void
test(S s)19 test(S s)
20 {
21     const S& cs = s;
22     typename S::reverse_iterator e = s.rend();
23     typename S::const_reverse_iterator ce1 = cs.rend();
24     typename S::const_reverse_iterator ce2 = s.crend();
25 
26     if (s.empty())
27     {
28         assert(  e ==  s.rbegin());
29         assert(ce1 == cs.rbegin());
30         assert(ce2 ==  s.rbegin());
31     }
32     else
33     {
34         assert(  e !=  s.rbegin());
35         assert(ce1 != cs.rbegin());
36         assert(ce2 !=  s.rbegin());
37     }
38 
39     assert(  e -  s.rbegin() == s.size());
40     assert(ce1 - cs.rbegin() == cs.size());
41     assert(ce2 - s.crbegin() == s.size());
42 
43     assert(  e == ce1);
44     assert(  e == ce2);
45     assert(ce1 == ce2);
46 }
47 
48 
main()49 int main()
50 {
51     typedef std::experimental::string_view    string_view;
52     typedef std::experimental::u16string_view u16string_view;
53     typedef std::experimental::u32string_view u32string_view;
54     typedef std::experimental::wstring_view   wstring_view;
55 
56     test(string_view   ());
57     test(u16string_view());
58     test(u32string_view());
59     test(wstring_view  ());
60     test(string_view   ( "123"));
61     test(wstring_view  (L"123"));
62 #if __cplusplus >= 201103L
63     test(u16string_view{u"123"});
64     test(u32string_view{U"123"});
65 #endif
66 }
67