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// bool empty() const noexcept; // 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 ASSERT_NOEXCEPT(s.empty());
22 assert(s.empty() == (s.size() == 0));
23}
24
25template <class S>
26TEST_CONSTEXPR_CXX20 void test_string() {
27 test(S());
28 test(S("123"));
29 test(S("12345678901234567890123456789012345678901234567890"));
30}
31
32TEST_CONSTEXPR_CXX20 bool test() {
33 test_string<std::string>();
34#if TEST_STD_VER >= 11
35 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
36#endif
37
38 return true;
39}
40
41int main(int, char**) {
42 test();
43#if TEST_STD_VER > 17
44 static_assert(test());
45#endif
46
47 return 0;
48}
49

source code of libcxx/test/std/strings/basic.string/string.capacity/empty.pass.cpp