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>
10
11// const_iterator cbegin() const; // constexpr since C++20
12
13#include <string>
14#include <cassert>
15
16#include "test_macros.h"
17#include "min_allocator.h"
18
19template <class S>
20TEST_CONSTEXPR_CXX20 void test(const S& s) {
21 typename S::const_iterator cb = s.cbegin();
22 if (!s.empty()) {
23 assert(*cb == s[0]);
24 }
25 assert(cb == s.begin());
26}
27
28template <class S>
29TEST_CONSTEXPR_CXX20 void test_string() {
30 test(S());
31 test(S("123"));
32}
33
34TEST_CONSTEXPR_CXX20 bool test() {
35 test_string<std::string>();
36#if TEST_STD_VER >= 11
37 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
38#endif
39
40 return true;
41}
42
43int main(int, char**) {
44 test();
45#if TEST_STD_VER > 17
46 static_assert(test());
47#endif
48
49 return 0;
50}
51

source code of libcxx/test/std/strings/basic.string/string.iterators/cbegin.pass.cpp