libstdc++-v3/testsuite/23_containers/unordered_map/modifiers/reserve.cc

   1 // { dg-options "-std=gnu++0x" }
   2
   3 // Copyright (C) 2012-2014 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 #include <unordered_map>
  21 #include <testsuite_hooks.h>
  22
  23 bool test __attribute__((unused)) = true;
  24
  25 void test01()
  26 {
  27   const int N = 1000;
  28
  29   typedef std::unordered_map<int, int> Map;
  30   Map m;
  31   m.reserve(N);
  32
  33   std::size_t bkts = m.bucket_count();
  34   for (int i = 0; i != N; ++i)
  35     {
  36       m.insert(std::make_pair(i, i));
  37       // As long as we insert less than the reserved number of elements we
  38       // shouldn't experiment any rehash.
  39       VERIFY( m.bucket_count() == bkts );
  40     }
  41 }
  42
  43 int main()
  44 {
  45   test01();
  46   return 0;
  47 }