libstdc++-v3/testsuite/23_containers/unordered_set/hash_policy/71181.cc

   1 // Copyright (C) 2016 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8 //
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17 //
  18 // { dg-do run { target c++11 } }
  19
  20 #include <unordered_set>
  21
  22 #include <testsuite_hooks.h>
  23
  24 template<typename _USet>
  25   void test(int threshold)
  26   {
  27     bool test __attribute__((unused)) = true;
  28     _USet us;
  29     auto nb_reserved = us.bucket_count();
  30     us.reserve(nb_reserved);
  31     auto bkts = us.bucket_count();
  32     for (int i = 0; i != threshold; ++i)
  33       {
  34         if (i == nb_reserved)
  35           {
  36             nb_reserved = bkts;
  37             us.reserve(nb_reserved);
  38             bkts = us.bucket_count();
  39           }
  40
  41         us.insert(i);
  42
  43         VERIFY( us.bucket_count() == bkts );
  44       }
  45   }
  46
  47 template<typename _Value>
  48   using unordered_set_power2_rehash =
  49   std::_Hashtable<_Value, _Value, std::allocator<_Value>,
  50                   std::__detail::_Identity,
  51                   std::equal_to<_Value>,
  52                   std::hash<_Value>,
  53                   std::__detail::_Mask_range_hashing,
  54                   std::__detail::_Default_ranged_hash,
  55                   std::__detail::_Power2_rehash_policy,
  56                   std::__detail::_Hashtable_traits<false, true, true>>;
  57
  58 int main()
  59 {
  60   test<std::unordered_set<int>>(150);
  61   test<unordered_set_power2_rehash<int>>(150);
  62   return 0;
  63 }