libstdc++-v3/testsuite/23_containers/unordered_set/hash_policy/26132.cc

   1 // { dg-options "-std=gnu++0x" }
   2
   3 // 2010-08-13  Paolo Carlini  <paolo.carlini@oracle.com>
   4 //
   5 // Copyright (C) 2010-2013 Free Software Foundation, Inc.
   6 //
   7 // This file is part of the GNU ISO C++ Library.  This library is free
   8 // software; you can redistribute it and/or modify it under the
   9 // terms of the GNU General Public License as published by the
  10 // Free Software Foundation; either version 3, or (at your option)
  11 // any later version.
  12 //
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License along
  19 // with this library; see the file COPYING3.  If not see
  20 // <http://www.gnu.org/licenses/>.
  21
  22 #include <unordered_set>
  23 #include <testsuite_hooks.h>
  24
  25 // libstdc++/26132
  26 void test01()
  27 {
  28   bool test __attribute__((unused)) = true;
  29
  30   for (float lf = 1.0; lf < 101.0; lf *= 10.0)
  31     for (int size = 1; size <= 6561; size *= 3)
  32       {
  33         std::unordered_set<int> us1;
  34         typedef std::unordered_set<int>::size_type size_type;
  35
  36         us1.max_load_factor(10.0);
  37
  38         for (int i = 0; i < size; ++i)
  39           us1.insert(i);
  40
  41         us1.max_load_factor(lf);
  42
  43         for (int i = 1; i <= 6561; i *= 81)
  44           {
  45             const size_type n = size * 81 / i;
  46             us1.rehash(n);
  47             VERIFY( us1.bucket_count() > us1.size() / us1.max_load_factor() );
  48             VERIFY( us1.bucket_count() >= n );
  49           }
  50       }
  51 }
  52
  53 int main()
  54 {
  55   test01();
  56   return 0;
  57 }