libstdc++-v3/testsuite/23_containers/unordered_multiset/insert/52476.cc

   1 // { dg-do run { target c++11 } }
   2 //
   3 // Copyright (C) 2012-2023 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_set>
  21 #include <vector>
  22 #include <algorithm>
  23 #include <testsuite_hooks.h>
  24
  25 namespace
  26 {
  27   struct pair_hash
  28   {
  29     std::size_t
  30     operator()(const std::pair<int, int>& p) const noexcept
  31     { return std::hash<int>()(p.first); }
  32   };
  33
  34   struct pair_equal_to
  35   {
  36     bool
  37     operator()(const std::pair<int, int>& x,
  38                const std::pair<int, int>& y) const noexcept
  39     { return x.first == y.first; }
  40   };
  41 }
  42
  43 void test01()
  44 {
  45   using namespace std;
  46
  47   unordered_multiset<pair<int, int>, pair_hash, pair_equal_to> mset;
  48   vector<int> values;
  49
  50   size_t nb_bkts = mset.bucket_count();
  51   int i = 0;
  52   for (;; ++i)
  53     {
  54       mset.insert(make_pair(0, i));
  55       if (mset.bucket_count() != nb_bkts)
  56         // Container got rehash
  57         break;
  58       values.clear();
  59       transform(mset.begin(), mset.end(), back_inserter(values),
  60                 [](const pair<int, int>& p) { return p.second; });
  61     }
  62
  63   vector<int> rehash_values;
  64   transform(mset.begin(), mset.end(), back_inserter(rehash_values),
  65             [](const pair<int, int>& p) { return p.second; });
  66   // Remove the value that result in a rehash
  67   rehash_values.erase(remove(rehash_values.begin(), rehash_values.end(), i));
  68
  69   VERIFY( rehash_values == values );
  70 }
  71
  72 int main()
  73 {
  74   test01();
  75   return 0;
  76 }