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// UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14)
10
11// <string_view>
12
13// constexpr const _CharT& operator[](size_type _pos) const;
14
15#include <string_view>
16#include <cassert>
17
18#include "test_macros.h"
19
20template <typename CharT>
21void test(const CharT* s, std::size_t len) {
22 typedef std::basic_string_view<CharT> SV;
23 SV sv(s, len);
24 ASSERT_SAME_TYPE(decltype(sv[0]), typename SV::const_reference);
25 LIBCPP_ASSERT_NOEXCEPT(sv[0]);
26 assert(sv.length() == len);
27 for (std::size_t i = 0; i < len; ++i) {
28 assert(sv[i] == s[i]);
29 assert(&sv[i] == s + i);
30 }
31}
32
33int main(int, char**) {
34 test(s: "ABCDE", len: 5);
35 test(s: "a", len: 1);
36
37#ifndef TEST_HAS_NO_WIDE_CHARACTERS
38 test(s: L"ABCDE", len: 5);
39 test(s: L"a", len: 1);
40#endif
41
42#if TEST_STD_VER >= 11
43 test(u"ABCDE", 5);
44 test(u"a", 1);
45
46 test(U"ABCDE", 5);
47 test(U"a", 1);
48#endif
49
50#if TEST_STD_VER > 11
51 {
52 constexpr std::basic_string_view<char> sv("ABC", 2);
53 static_assert(sv.length() == 2, "");
54 static_assert(sv[0] == 'A', "");
55 static_assert(sv[1] == 'B', "");
56 }
57#endif
58
59 return 0;
60}
61

source code of libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp