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// reverse_iterator rbegin(); // constexpr since C++20
12// const_reverse_iterator rbegin() const; // constexpr since C++20
13
14#include <string>
15#include <cassert>
16
17#include "test_macros.h"
18#include "min_allocator.h"
19
20template <class S>
21TEST_CONSTEXPR_CXX20 void test(S s) {
22 const S& cs = s;
23 typename S::reverse_iterator b = s.rbegin();
24 typename S::const_reverse_iterator cb = cs.rbegin();
25 if (!s.empty()) {
26 assert(*b == s.back());
27 }
28 assert(b == cb);
29}
30
31template <class S>
32TEST_CONSTEXPR_CXX20 void test_string() {
33 test(S());
34 test(S("123"));
35}
36
37TEST_CONSTEXPR_CXX20 bool test() {
38 test_string<std::string>();
39#if TEST_STD_VER >= 11
40 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
41#endif
42
43 return true;
44}
45
46int main(int, char**) {
47 test();
48#if TEST_STD_VER > 17
49 static_assert(test());
50#endif
51
52 return 0;
53}
54

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