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