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& operator[](size_type _pos) const;
13 
14 #include <string_view>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 
19 template <typename CharT>
20 void 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[0]), typename SV::const_reference);
24     LIBCPP_ASSERT_NOEXCEPT(   sv[0]);
25     assert ( sv.length() == len );
26     for ( size_t i = 0; i < len; ++i ) {
27         assert ( sv[i] == s[i] );
28         assert ( &sv[i] == s + i );
29         }
30     }
31 
32 int main(int, char**) {
33     test ( "ABCDE", 5 );
34     test ( "a", 1 );
35 
36     test ( L"ABCDE", 5 );
37     test ( L"a", 1 );
38 
39 #if TEST_STD_VER >= 11
40     test ( u"ABCDE", 5 );
41     test ( u"a", 1 );
42 
43     test ( U"ABCDE", 5 );
44     test ( U"a", 1 );
45 #endif
46 
47 #if TEST_STD_VER > 11
48     {
49     constexpr std::basic_string_view<char> sv ( "ABC", 2 );
50     static_assert ( sv.length() ==  2,  "" );
51     static_assert ( sv[0]  == 'A', "" );
52     static_assert ( sv[1]  == 'B', "" );
53     }
54 #endif
55 
56   return 0;
57 }
58