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

   1 // Copyright (C) 2004 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 2, 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 COPYING.  If not, write to the Free
  16 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  17 // USA.
  18
  19 #include <list>
  20 #include <ext/new_allocator.h>
  21
  22 using namespace std;
  23 using __gnu_cxx::new_allocator;
  24
  25 template<typename T>
  26   class clear_alloc : public new_allocator<T>
  27   {
  28   public:
  29
  30     template <typename T1>
  31       struct rebind
  32       { typedef clear_alloc<T1> other; };
  33
  34     virtual void clear() throw()
  35     { }
  36
  37     clear_alloc() throw()
  38     { }
  39
  40     clear_alloc(clear_alloc const&) throw() : new_allocator<T>()
  41     { }
  42
  43     template<typename T1>
  44     clear_alloc(clear_alloc<T1> const&) throw()
  45       { }
  46
  47     virtual ~clear_alloc() throw()
  48     { this->clear(); }
  49
  50     T* allocate(typename new_allocator<T>::size_type n, const void *hint = 0)
  51     {
  52       this->clear();
  53       return new_allocator<T>::allocate(n, hint);
  54     }
  55
  56     void deallocate(T *ptr, typename new_allocator<T>::size_type n)
  57     {
  58       this->clear();
  59       new_allocator<T>::deallocate(ptr, n);
  60     }
  61   };
  62
  63 template<typename Container>
  64   void Check_Container()
  65   {
  66     Container* pic = new Container;
  67     int x = 230;
  68
  69     while (x--)
  70       {
  71         pic->push_back(x);
  72       }
  73
  74     pic->get_allocator();
  75
  76     // The following has led to infinite recursions or cores.
  77     pic->clear();
  78
  79     delete pic;
  80   }
  81
  82
  83 int main()
  84 {
  85   Check_Container<std::list<int, clear_alloc<int> > >();
  86   return 0;
  87 }
  88