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