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
10 // <string_view>
11
12 // constexpr const _CharT& back();
13
14 #include <string_view>
15 #include <cassert>
16
17 #include "test_macros.h"
18
19 template <typename CharT>
test(const CharT * s,size_t len)20 bool test ( const CharT *s, size_t len ) {
21 typedef std::basic_string_view<CharT> SV;
22 SV sv ( s, len );
23 ASSERT_SAME_TYPE(decltype(sv.front()), typename SV::const_reference);
24 LIBCPP_ASSERT_NOEXCEPT( sv.front());
25 assert ( sv.length() == len );
26 assert ( sv.front() == s[0] );
27 return &sv.front() == s;
28 }
29
main(int,char **)30 int main(int, char**) {
31 assert ( test ( "ABCDE", 5 ));
32 assert ( test ( "a", 1 ));
33
34 assert ( test ( L"ABCDE", 5 ));
35 assert ( test ( L"a", 1 ));
36
37 #if TEST_STD_VER >= 11
38 assert ( test ( u"ABCDE", 5 ));
39 assert ( test ( u"a", 1 ));
40
41 assert ( test ( U"ABCDE", 5 ));
42 assert ( test ( U"a", 1 ));
43 #endif
44
45 #if TEST_STD_VER >= 11
46 {
47 constexpr std::basic_string_view<char> sv ( "ABC", 2 );
48 static_assert ( sv.length() == 2, "" );
49 static_assert ( sv.front() == 'A', "" );
50 }
51 #endif
52
53 return 0;
54 }
55