libstdc++-v3/testsuite/23_containers/unordered_map/final_hash.cc

   1 // { dg-do compile }
   2 // { dg-options "-std=gnu++11" }
   3
   4 // Copyright (C) 2011-2015 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 #include <string>
  22 #include <unordered_map>
  23
  24 namespace
  25 {
  26   template<typename _Tp>
  27   struct final_hash final
  28   {
  29     std::size_t operator() (const _Tp&) const noexcept
  30     { return 0; }
  31   };
  32 }
  33
  34 // A non-integral type:
  35 template class std::unordered_map<std::string, int, final_hash<std::string>>;
  36
  37 // An integral type;
  38 template class std::unordered_map<int, int, final_hash<int>>;
  39