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 // constexpr const_iterator begin() 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::iterator b = s.begin();
26 typename S::const_iterator cb1 = cs.begin();
27 typename S::const_iterator cb2 = s.cbegin();
28 if (!s.empty())
29 {
30 assert( *b == s[0]);
31 assert( &*b == &s[0]);
32 assert( *cb1 == s[0]);
33 assert(&*cb1 == &s[0]);
34 assert( *cb2 == s[0]);
35 assert(&*cb2 == &s[0]);
36
37 }
38 assert( b == cb1);
39 assert( b == cb2);
40 assert(cb1 == cb2);
41 }
42
43
main(int,char **)44 int main(int, char**)
45 {
46 typedef std::string_view string_view;
47 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
48 typedef std::u8string_view u8string_view;
49 #endif
50 typedef std::u16string_view u16string_view;
51 typedef std::u32string_view u32string_view;
52
53 test(string_view ());
54 test(u16string_view());
55 test(u32string_view());
56 test(string_view ( "123"));
57 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
58 test(u8string_view{u8"123"});
59 #endif
60 #if TEST_STD_VER >= 11
61 test(u16string_view{u"123"});
62 test(u32string_view{U"123"});
63 #endif
64
65 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
66 typedef std::wstring_view wstring_view;
67 test(wstring_view ());
68 test(wstring_view (L"123"));
69 #endif
70
71 #if TEST_STD_VER > 11
72 {
73 constexpr string_view sv { "123", 3 };
74 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
75 constexpr u8string_view u8sv {u8"123", 3 };
76 #endif
77 constexpr u16string_view u16sv {u"123", 3 };
78 constexpr u32string_view u32sv {U"123", 3 };
79
80 static_assert ( *sv.begin() == sv[0], "" );
81 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
82 static_assert ( *u8sv.begin() == u8sv[0], "" );
83 #endif
84 static_assert ( *u16sv.begin() == u16sv[0], "" );
85 static_assert ( *u32sv.begin() == u32sv[0], "" );
86
87 static_assert ( *sv.cbegin() == sv[0], "" );
88 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
89 static_assert ( *u8sv.cbegin() == u8sv[0], "" );
90 #endif
91 static_assert ( *u16sv.cbegin() == u16sv[0], "" );
92 static_assert ( *u32sv.cbegin() == u32sv[0], "" );
93
94 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
95 {
96 constexpr wstring_view wsv {L"123", 3 };
97 static_assert ( *wsv.begin() == wsv[0], "" );
98 static_assert ( *wsv.cbegin() == wsv[0], "" );
99 }
100 #endif
101 }
102 #endif // TEST_STD_VER > 11
103
104 return 0;
105 }
106