libstdc++-v3/testsuite/23_containers/unordered_map/cons/56112.cc

   1 // { dg-do run { target c++11 } }
   2
   3 // Copyright (C) 2013-2021 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_map>
  21 #include <utility>
  22
  23 struct Key
  24 {
  25   explicit Key(const int* p) : value(p) { }
  26   ~Key() { value = nullptr; }
  27
  28   bool operator==(const Key& k) const { return *value == *k.value; }
  29
  30   const int* value;
  31 };
  32
  33 struct hash
  34 {
  35   std::size_t operator()(const Key& k) const noexcept { return *k.value; }
  36 };
  37
  38 struct S
  39 {
  40   int value;
  41   operator std::pair<const Key, int>() const { return {Key(&value), value}; }
  42 };
  43
  44 int main()
  45 {
  46     S s[1] = { {2} };
  47     std::unordered_map<Key, int, hash> m(s, s+1);
  48     std::unordered_multimap<Key, int, hash> mm(s, s+1);
  49 }