libstdc++-v3/testsuite/21_strings/basic_string/capacity/char/1.cc

   1 // 1999-05-11 bkoz
   2
   3 // Copyright (C) 1999-2022 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // { dg-options "-Wno-stringop-overflow" }
  21
  22 // 21.3.3 string capacity
  23
  24 #include <string>
  25 #include <testsuite_hooks.h>
  26
  27 void test01()
  28 {
  29   // POD types : resize, capacity, reserve
  30   std::string str01;
  31   typedef std::string::size_type size_type_s;
  32
  33   size_type_s sz01 = str01.capacity();
  34   str01.reserve(100);
  35   size_type_s sz02 = str01.capacity();
  36   VERIFY( sz02 >= sz01 );
  37   VERIFY( sz02 >= 100 );
  38 #if __cplusplus <= 201703L
  39   str01.reserve();
  40 #else
  41   str01.shrink_to_fit(); // reserve is deprecated in C++20
  42 #endif
  43   sz01 = str01.capacity();
  44   VERIFY( sz01 < sz02 );
  45
  46   // P0966: reserve should not shrink
  47   str01.reserve(100);
  48   sz01 = str01.capacity();
  49   str01.reserve(sz01 - 1);
  50   VERIFY( str01.capacity() == sz01 );
  51
  52   sz01 = str01.size() + 5;
  53   str01.resize(sz01);
  54   sz02 = str01.size();
  55   VERIFY( sz01 == sz02 );
  56
  57   sz01 = str01.size() - 5;
  58   str01.resize(sz01);
  59   sz02 = str01.size();
  60   VERIFY( sz01 == sz02 );
  61
  62   std::string str05(30, 'q');
  63   std::string str06 = str05;
  64   // The following triggers -Wstringop-overflow.  See PR 103332.
  65   str05 = str06 + str05;
  66   VERIFY( str05.capacity() >= str05.size() );
  67   VERIFY( str06.capacity() >= str06.size() );
  68
  69   // POD types: size, length, max_size, clear(), empty()
  70   bool b01;
  71   std::string str011;
  72   b01 = str01.empty();
  73   VERIFY( b01 == true );
  74   sz01 = str01.size();
  75   sz02 = str01.length();
  76   VERIFY( sz01 == sz02 );
  77   str01.c_str();
  78   sz01 = str01.size();
  79   sz02 = str01.length();
  80   VERIFY( sz01 == sz02 );
  81
  82   sz01 = str01.length();
  83   str01.c_str();
  84   str011 = str01 +  "_addendum_";
  85   str01.c_str();
  86   sz02 = str01.length();
  87   VERIFY( sz01 == sz02 );
  88   sz02 = str011.length();
  89   VERIFY( sz02 > sz01 );
  90
  91   // trickster allocator issues involved with these:
  92   std::string str3 = "8-chars_8-chars_";
  93   std::string str4 = str3 + "7-chars";
  94
  95   sz01 = str01.size();
  96   sz02 = str01.max_size();
  97   VERIFY( sz02 >= sz01 );
  98
  99   sz01 = str01.size();
 100   str01.clear();
 101   b01 = str01.empty();
 102   VERIFY( b01 == true );
 103   sz02 = str01.size();
 104   VERIFY( sz01 >= sz02 );
 105 }
 106
 107 int main()
 108 {
 109   test01();
 110   return 0;
 111 }