xref: /llvm-project/libcxx/test/std/strings/basic.string/string.capacity/clear.pass.cpp (revision a40bada91aeda276a772acfbcae6e8de26755a11)
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 // void clear(); // constexpr since C++20
12 
13 #include <string>
14 #include <cassert>
15 
16 #include "test_macros.h"
17 #include "min_allocator.h"
18 
19 template <class S>
20 TEST_CONSTEXPR_CXX20 void test(S s) {
21   s.clear();
22   assert(s.size() == 0);
23 }
24 
25 template <class S>
26 TEST_CONSTEXPR_CXX20 void test_string() {
27   S s;
28   test(s);
29 
30   s.assign(10, 'a');
31   s.erase(5);
32   test(s);
33 
34   s.assign(100, 'a');
35   s.erase(50);
36   test(s);
37 }
38 
39 TEST_CONSTEXPR_CXX20 bool test() {
40   test_string<std::string>();
41 #if TEST_STD_VER >= 11
42   test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
43 #endif
44 
45   return true;
46 }
47 
48 int main(int, char**) {
49   test();
50 #if TEST_STD_VER > 17
51   static_assert(test());
52 #endif
53 
54   return 0;
55 }
56