libstdc++-v3/testsuite/23_containers/list/cons/clear_allocator.h

   1 // Copyright (C) 2004, 2009 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 #include <ext/new_allocator.h>
  19
  20 using namespace std;
  21 using __gnu_cxx::new_allocator;
  22
  23 template<typename T>
  24   class clear_alloc : public new_allocator<T>
  25   {
  26   public:
  27
  28     template <typename T1>
  29       struct rebind
  30       { typedef clear_alloc<T1> other; };
  31
  32     virtual void clear() throw()
  33     { }
  34
  35     clear_alloc() throw()
  36     { }
  37
  38     clear_alloc(clear_alloc const&) throw() : new_allocator<T>()
  39     { }
  40
  41     template<typename T1>
  42     clear_alloc(clear_alloc<T1> const&) throw()
  43       { }
  44
  45     virtual ~clear_alloc() throw()
  46     { this->clear(); }
  47
  48     T* allocate(typename new_allocator<T>::size_type n, const void *hint = 0)
  49     {
  50       this->clear();
  51       return new_allocator<T>::allocate(n, hint);
  52     }
  53
  54     void deallocate(T *ptr, typename new_allocator<T>::size_type n)
  55     {
  56       this->clear();
  57       new_allocator<T>::deallocate(ptr, n);
  58     }
  59   };
  60
  61 template<typename Container>
  62   void Check_Container()
  63   {
  64     Container* pic = new Container;
  65     int x = 230;
  66
  67     while (x--)
  68       {
  69         pic->push_back(x);
  70       }
  71
  72     pic->get_allocator();
  73
  74     // The following has led to infinite recursions or cores.
  75     pic->clear();
  76
  77     delete pic;
  78   }