libcxx/test/std/strings/basic.string/string.capacity/clear.pass.cpp

   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 }