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 <experimental/string_view>
15 #include <cassert>
16
17 template <class S>
18 void
test(S s)19 test(S s)
20 {
21 const S& cs = s;
22 typename S::iterator b = s.begin();
23 typename S::const_iterator cb1 = cs.begin();
24 typename S::const_iterator cb2 = s.cbegin();
25 if (!s.empty())
26 {
27 assert( *b == s[0]);
28 assert( &*b == &s[0]);
29 assert( *cb1 == s[0]);
30 assert(&*cb1 == &s[0]);
31 assert( *cb2 == s[0]);
32 assert(&*cb2 == &s[0]);
33
34 }
35 assert( b == cb1);
36 assert( b == cb2);
37 assert(cb1 == cb2);
38 }
39
40
main()41 int main()
42 {
43 typedef std::experimental::string_view string_view;
44 typedef std::experimental::u16string_view u16string_view;
45 typedef std::experimental::u32string_view u32string_view;
46 typedef std::experimental::wstring_view wstring_view;
47
48 test(string_view ());
49 test(u16string_view());
50 test(u32string_view());
51 test(wstring_view ());
52 test(string_view ( "123"));
53 test(wstring_view (L"123"));
54 #if __cplusplus >= 201103L
55 test(u16string_view{u"123"});
56 test(u32string_view{U"123"});
57 #endif
58
59 #if _LIBCPP_STD_VER > 11
60 {
61 constexpr string_view sv { "123", 3 };
62 constexpr u16string_view u16sv {u"123", 3 };
63 constexpr u32string_view u32sv {U"123", 3 };
64 constexpr wstring_view wsv {L"123", 3 };
65
66 static_assert ( *sv.begin() == sv[0], "" );
67 static_assert ( *u16sv.begin() == u16sv[0], "" );
68 static_assert ( *u32sv.begin() == u32sv[0], "" );
69 static_assert ( *wsv.begin() == wsv[0], "" );
70
71 static_assert ( *sv.cbegin() == sv[0], "" );
72 static_assert ( *u16sv.cbegin() == u16sv[0], "" );
73 static_assert ( *u32sv.cbegin() == u32sv[0], "" );
74 static_assert ( *wsv.cbegin() == wsv[0], "" );
75 }
76 #endif
77 }
78