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 begin() const;
13
14 #include <string_view>
15 #include <cassert>
16
17 #include "test_macros.h"
18
19 template <class S>
20 void
test(S s)21 test(S s)
22 {
23 const S& cs = s;
24 typename S::iterator b = s.begin();
25 typename S::const_iterator cb1 = cs.begin();
26 typename S::const_iterator cb2 = s.cbegin();
27 if (!s.empty())
28 {
29 assert( *b == s[0]);
30 assert( &*b == &s[0]);
31 assert( *cb1 == s[0]);
32 assert(&*cb1 == &s[0]);
33 assert( *cb2 == s[0]);
34 assert(&*cb2 == &s[0]);
35
36 }
37 assert( b == cb1);
38 assert( b == cb2);
39 assert(cb1 == cb2);
40 }
41
42
main()43 int main()
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 typedef std::wstring_view wstring_view;
52
53 test(string_view ());
54 test(u16string_view());
55 test(u32string_view());
56 test(wstring_view ());
57 test(string_view ( "123"));
58 test(wstring_view (L"123"));
59 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
60 test(u8string_view{u8"123"});
61 #endif
62 #if TEST_STD_VER >= 11
63 test(u16string_view{u"123"});
64 test(u32string_view{U"123"});
65 #endif
66
67 #if TEST_STD_VER > 11
68 {
69 constexpr string_view sv { "123", 3 };
70 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
71 constexpr u8string_view u8sv {u8"123", 3 };
72 #endif
73 constexpr u16string_view u16sv {u"123", 3 };
74 constexpr u32string_view u32sv {U"123", 3 };
75 constexpr wstring_view wsv {L"123", 3 };
76
77 static_assert ( *sv.begin() == sv[0], "" );
78 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
79 static_assert ( *u8sv.begin() == u8sv[0], "" );
80 #endif
81 static_assert ( *u16sv.begin() == u16sv[0], "" );
82 static_assert ( *u32sv.begin() == u32sv[0], "" );
83 static_assert ( *wsv.begin() == wsv[0], "" );
84
85 static_assert ( *sv.cbegin() == sv[0], "" );
86 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
87 static_assert ( *u8sv.cbegin() == u8sv[0], "" );
88 #endif
89 static_assert ( *u16sv.cbegin() == u16sv[0], "" );
90 static_assert ( *u32sv.cbegin() == u32sv[0], "" );
91 static_assert ( *wsv.cbegin() == wsv[0], "" );
92 }
93 #endif
94 }
95