libstdc++-v3/testsuite/23_containers/unordered_set/buckets/swap.cc

   1 // { dg-do run { target c++11 } }
   2
   3 // Copyright (C) 2013-2025 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 <testsuite_hooks.h>
  21 #include <unordered_set>
  22
  23 namespace
  24 {
  25   struct hash
  26   {
  27     hash() = default;
  28     hash(int modulo)
  29       : _M_modulo(modulo)
  30     { }
  31
  32     std::size_t operator() (int val) const noexcept
  33     { return val % _M_modulo; }
  34
  35     int _M_modulo;
  36   };
  37 }
  38
  39 void
  40 test01()
  41 {
  42   // static_assert(std::__cache_default<int, hash>::value,
  43   //            "Unexpected default cache value");
  44   typedef std::unordered_set<int, hash> us_t;
  45   us_t us1(10, hash(13));
  46   us_t us2(10, hash(7));
  47
  48   VERIFY( us1.hash_function()._M_modulo == 13 );
  49   VERIFY( us2.hash_function()._M_modulo == 7 );
  50
  51   const int nb = 5;
  52   for (int i = 0; i != nb * us1.hash_function()._M_modulo; ++i)
  53     us1.insert(i);
  54
  55   us_t::local_iterator lit = us1.begin(12);
  56   us_t::local_iterator litend = us1.end(12);
  57   VERIFY( std::distance(lit, litend) == nb );
  58
  59   us1.swap(us2);
  60
  61   VERIFY( us1.hash_function()._M_modulo == 7 );
  62   VERIFY( us2.hash_function()._M_modulo == 13 );
  63
  64   VERIFY( std::distance(lit, litend) == nb );
  65 }
  66
  67 int main()
  68 {
  69   test01();
  70 }