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 typedef std::u16string_view u16string_view;
47 typedef std::u32string_view u32string_view;
48 typedef std::wstring_view wstring_view;
49
50 test(string_view ());
51 test(u16string_view());
52 test(u32string_view());
53 test(wstring_view ());
54 test(string_view ( "123"));
55 test(wstring_view (L"123"));
56 #if TEST_STD_VER >= 11
57 test(u16string_view{u"123"});
58 test(u32string_view{U"123"});
59 #endif
60
61 #if TEST_STD_VER > 11
62 {
63 constexpr string_view sv { "123", 3 };
64 constexpr u16string_view u16sv {u"123", 3 };
65 constexpr u32string_view u32sv {U"123", 3 };
66 constexpr wstring_view wsv {L"123", 3 };
67
68 static_assert ( *sv.begin() == sv[0], "" );
69 static_assert ( *u16sv.begin() == u16sv[0], "" );
70 static_assert ( *u32sv.begin() == u32sv[0], "" );
71 static_assert ( *wsv.begin() == wsv[0], "" );
72
73 static_assert ( *sv.cbegin() == sv[0], "" );
74 static_assert ( *u16sv.cbegin() == u16sv[0], "" );
75 static_assert ( *u32sv.cbegin() == u32sv[0], "" );
76 static_assert ( *wsv.cbegin() == wsv[0], "" );
77 }
78 #endif
79 }
80