xref: /llvm-project/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp (revision 053d81ceebe9a54255c49801b88ab61b5d03060a)
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 <string_view>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 
19 template <class S>
20 void
21 test(S s)
22 {
23     const S& cs = s;
24     typename S::reverse_iterator e = s.rend();
25     typename S::const_reverse_iterator ce1 = cs.rend();
26     typename S::const_reverse_iterator ce2 = s.crend();
27 
28     if (s.empty())
29     {
30         assert(  e ==  s.rbegin());
31         assert(ce1 == cs.rbegin());
32         assert(ce2 ==  s.rbegin());
33     }
34     else
35     {
36         assert(  e !=  s.rbegin());
37         assert(ce1 != cs.rbegin());
38         assert(ce2 !=  s.rbegin());
39     }
40 
41     assert(  e -  s.rbegin() == s.size());
42     assert(ce1 - cs.rbegin() == cs.size());
43     assert(ce2 - s.crbegin() == s.size());
44 
45     assert(  e == ce1);
46     assert(  e == ce2);
47     assert(ce1 == ce2);
48 }
49 
50 
51 int main()
52 {
53     typedef std::string_view    string_view;
54     typedef std::u16string_view u16string_view;
55     typedef std::u32string_view u32string_view;
56     typedef std::wstring_view   wstring_view;
57 
58     test(string_view   ());
59     test(u16string_view());
60     test(u32string_view());
61     test(wstring_view  ());
62     test(string_view   ( "123"));
63     test(wstring_view  (L"123"));
64 #if TEST_STD_VER >= 11
65     test(u16string_view{u"123"});
66     test(u32string_view{U"123"});
67 #endif
68 }
69