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// <string_view>
10
11// constexpr const _CharT& at(size_type _pos) const;
12
13#include <string_view>
14#include <stdexcept>
15#include <cassert>
16
17#include "test_macros.h"
18
19template <typename CharT>
20void test(const CharT* s, std::size_t len) {
21 std::basic_string_view<CharT> sv(s, len);
22 assert(sv.length() == len);
23 for (std::size_t i = 0; i < len; ++i) {
24 assert(sv.at(i) == s[i]);
25 assert(&sv.at(i) == s + i);
26 }
27
28#ifndef TEST_HAS_NO_EXCEPTIONS
29 try {
30 (void)sv.at(len);
31 } catch (const std::out_of_range&) {
32 return;
33 }
34 assert(false);
35#endif
36}
37
38int main(int, char**) {
39 test(s: "ABCDE", len: 5);
40 test(s: "a", len: 1);
41
42#ifndef TEST_HAS_NO_WIDE_CHARACTERS
43 test(s: L"ABCDE", len: 5);
44 test(s: L"a", len: 1);
45#endif
46
47#if TEST_STD_VER >= 11
48 test(u"ABCDE", 5);
49 test(u"a", 1);
50
51 test(U"ABCDE", 5);
52 test(U"a", 1);
53#endif
54
55#if TEST_STD_VER >= 11
56 {
57 constexpr std::basic_string_view<char> sv("ABC", 2);
58 static_assert(sv.length() == 2, "");
59 static_assert(sv.at(0) == 'A', "");
60 static_assert(sv.at(1) == 'B', "");
61 }
62#endif
63
64 return 0;
65}
66

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