1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14)
10 
11 // <string_view>
12 
13 // const_iterator rbegin() const;
14 
15 #include <string_view>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 
20 template <class S>
21 void
test(S s)22 test(S s)
23 {
24     const S& cs = s;
25     typename S::reverse_iterator b = s.rbegin();
26     typename S::const_reverse_iterator cb1 = cs.rbegin();
27     typename S::const_reverse_iterator cb2 = s.crbegin();
28     if (!s.empty())
29     {
30         const size_t last = s.size() - 1;
31         assert(   *b ==  s[last]);
32         assert(  &*b == &s[last]);
33         assert( *cb1 ==  s[last]);
34         assert(&*cb1 == &s[last]);
35         assert( *cb2 ==  s[last]);
36         assert(&*cb2 == &s[last]);
37 
38     }
39     assert(  b == cb1);
40     assert(  b == cb2);
41     assert(cb1 == cb2);
42 }
43 
44 
main(int,char **)45 int main(int, char**)
46 {
47     typedef std::string_view    string_view;
48 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
49     typedef std::u8string_view  u8string_view;
50 #endif
51     typedef std::u16string_view u16string_view;
52     typedef std::u32string_view u32string_view;
53 
54     test(string_view   ());
55     test(u16string_view());
56     test(u32string_view());
57     test(string_view   ( "123"));
58 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
59     test(u8string_view{u8"123"});
60 #endif
61 #if TEST_STD_VER >= 11
62     test(u16string_view{u"123"});
63     test(u32string_view{U"123"});
64 #endif
65 
66 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
67     typedef std::wstring_view   wstring_view;
68     test(wstring_view  ());
69     test(wstring_view  (L"123"));
70 #endif
71 
72 #if TEST_STD_VER > 14
73     {
74     constexpr string_view       sv { "123", 3 };
75 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
76     constexpr u8string_view u8sv  {u8"123", 3 };
77 #endif
78     constexpr u16string_view u16sv {u"123", 3 };
79     constexpr u32string_view u32sv {U"123", 3 };
80 
81     static_assert (    *sv.rbegin() ==    sv[2], "" );
82 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
83     static_assert (  *u8sv.rbegin() ==  u8sv[2], "" );
84 #endif
85     static_assert ( *u16sv.rbegin() == u16sv[2], "" );
86     static_assert ( *u32sv.rbegin() == u32sv[2], "" );
87 
88     static_assert (    *sv.crbegin() ==    sv[2], "" );
89 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
90     static_assert (  *u8sv.crbegin() == u8sv[2], "" );
91 #endif
92     static_assert ( *u16sv.crbegin() == u16sv[2], "" );
93     static_assert ( *u32sv.crbegin() == u32sv[2], "" );
94 
95 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
96         {
97             constexpr wstring_view     wsv {L"123", 3 };
98             static_assert (   *wsv.rbegin() ==   wsv[2], "" );
99             static_assert (   *wsv.crbegin() ==   wsv[2], "" );
100         }
101 #endif
102     }
103 #endif // TEST_STD_VER > 14
104 
105   return 0;
106 }
107