libstdc++-v3/testsuite/23_containers/unordered_map/erase/51142.cc

   1 // Copyright (C) 2011-2025 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
  19 // { dg-do compile { target c++11 } }
  20
  21 #include <unordered_map>
  22
  23 struct X
  24 {
  25   template<typename T>
  26   X(T&) {}
  27 };
  28
  29 struct X_hash
  30 { std::size_t operator()(const X&) const { return 0; } };
  31
  32 bool operator==(const X&, const X&) { return false; }
  33
  34 // LWG 2059.
  35 void erasor(std::unordered_map<X, int, X_hash>& s, X x)
  36 {
  37   std::unordered_map<X, int, X_hash>::iterator it = s.find(x);
  38   if (it != s.end())
  39     s.erase(it);
  40 }