libstdc++-v3/testsuite/ext/pb_ds/example/hash_find_neg.cc

   1 // { dg-do compile }
   2 // -*- C++ -*-
   3
   4 // Copyright (C) 2005-2018 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 terms
   8 // of the GNU General Public License as published by the Free Software
   9 // Foundation; either version 3, or (at your option) any later
  10 // version.
  11
  12 // This library is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License
  18 // along with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21
  22 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  23
  24 // Permission to use, copy, modify, sell, and distribute this software
  25 // is hereby granted without fee, provided that the above copyright
  26 // notice appears in all copies, and that both that copyright notice
  27 // and this permission notice appear in supporting documentation. None
  28 // of the above authors, nor IBM Haifa Research Laboratories, make any
  29 // representation about the suitability of this software for any
  30 // purpose. It is provided "as is" without express or implied
  31 // warranty.
  32
  33 /**
  34  * @file hash_bad_find_example.cpp
  35  * An example showing how *not* to use unordered containers.
  36  */
  37
  38 /**
  39  * This non-compiling example shows wrong use of unordered
  40  * associative-containers. These types of containers have distinct
  41  * point-type and range-type iterator types.
  42  **/
  43
  44 #include <utility>
  45 #include <ext/pb_ds/assoc_container.hpp>
  46
  47 using namespace std;
  48 using namespace __gnu_pbds;
  49
  50 int main()
  51 {
  52   // A collision-chaining hash table mapping ints to chars.
  53   typedef cc_hash_table<int, char> map_t;
  54
  55   // A map_t object.
  56   map_t h;
  57
  58   // Insert a value mapping the int 1 to the char 'a'.
  59   h.insert(make_pair(1, 'a'));
  60
  61   // Find the entry of the key '1' the* wrong* way.
  62   // The following line will not compile, since map_t::find returns a
  63   // point-iterator, which, by design, is not convertible to a
  64   // range-iterator.
  65   map_t::iterator it = h.find(1); // { dg-error "conversion from" }
  66
  67   return 0;
  68 }
  69