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

   1 // Copyright (C) 2016-2022 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
  26   test(_USet& us, int threshold)
  27   {
  28     auto nb_reserved = us.bucket_count();
  29     us.reserve(nb_reserved);
  30     auto bkts = us.bucket_count();
  31     for (int nb_insert = 1; nb_insert <= threshold; ++nb_insert)
  32       {
  33         if (nb_insert > nb_reserved)
  34           {
  35             nb_reserved = bkts;
  36             us.reserve(nb_reserved);
  37             bkts = us.bucket_count();
  38           }
  39
  40         us.insert(nb_insert);
  41
  42         VERIFY( us.bucket_count() == bkts );
  43       }
  44   }
  45
  46 template<typename _Value>
  47   using unordered_set_power2_rehash =
  48   std::_Hashtable<_Value, _Value, std::allocator<_Value>,
  49                   std::__detail::_Identity,
  50                   std::equal_to<_Value>,
  51                   std::hash<_Value>,
  52                   std::__detail::_Mask_range_hashing,
  53                   std::__detail::_Default_ranged_hash,
  54                   std::__detail::_Power2_rehash_policy,
  55                   std::__detail::_Hashtable_traits<false, true, true>>;
  56
  57 template<typename _USet>
  58   void
  59   test_cont()
  60   {
  61     _USet us;
  62     test(us, 150);
  63
  64     us.clear();
  65     us.rehash(0);
  66
  67     test(us, 150);
  68   }
  69
  70 int main()
  71 {
  72   test_cont<std::unordered_set<int>>();
  73   test_cont<unordered_set_power2_rehash<int>>();
  74   return 0;
  75 }