libcxx/test/std/strings/basic.string/string.capacity/shrink_to_fit.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 shrink_to_fit();
  12
  13 #include <string>
  14 #include <cassert>
  15
  16 #include "test_macros.h"
  17 #include "min_allocator.h"
  18
  19 template <class S>
  20 void
  21 test(S s)
  22 {
  23     typename S::size_type old_cap = s.capacity();
  24     S s0 = s;
  25     s.shrink_to_fit();
  26     LIBCPP_ASSERT(s.__invariants());
  27     assert(s == s0);
  28     assert(s.capacity() <= old_cap);
  29     assert(s.capacity() >= s.size());
  30 }
  31
  32 int main(int, char**)
  33 {
  34     {
  35     typedef std::string S;
  36     S s;
  37     test(s);
  38
  39     s.assign(10, 'a');
  40     s.erase(5);
  41     test(s);
  42
  43     s.assign(100, 'a');
  44     s.erase(50);
  45     test(s);
  46     }
  47 #if TEST_STD_VER >= 11
  48     {
  49     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
  50     S s;
  51     test(s);
  52
  53     s.assign(10, 'a');
  54     s.erase(5);
  55     test(s);
  56
  57     s.assign(100, 'a');
  58     s.erase(50);
  59     test(s);
  60     }
  61 #endif
  62
  63   return 0;
  64 }