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

   1 // Copyright (C) 2004-2025 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 #include <deque>
  19 #include <ext/new_allocator.h>
  20
  21 using namespace std;
  22 using __gnu_cxx::new_allocator;
  23
  24 template<typename T>
  25   class clear_alloc : public new_allocator<T>
  26   {
  27   public:
  28
  29     template <typename T1>
  30       struct rebind
  31       { typedef clear_alloc<T1> other; };
  32
  33     virtual void clear() throw()
  34     { }
  35
  36     clear_alloc() throw()
  37     { }
  38
  39     clear_alloc(clear_alloc const&) throw() : new_allocator<T>()
  40     { }
  41
  42     template<typename T1>
  43     clear_alloc(clear_alloc<T1> const&) throw()
  44       { }
  45
  46     virtual ~clear_alloc() throw()
  47     { this->clear(); }
  48
  49     T* allocate(typename new_allocator<T>::size_type n, const void *hint = 0)
  50     {
  51       this->clear();
  52       return new_allocator<T>::allocate(n, hint);
  53     }
  54
  55     void deallocate(T *ptr, typename new_allocator<T>::size_type n)
  56     {
  57       this->clear();
  58       new_allocator<T>::deallocate(ptr, n);
  59     }
  60   };
  61
  62 template<typename Container>
  63   void Check_Container()
  64   {
  65     Container* pic = new Container;
  66     int x = 230;
  67
  68     while (x--)
  69       {
  70         pic->push_back(x);
  71       }
  72
  73     (void) pic->get_allocator();
  74
  75     // The following has led to infinite recursions or cores.
  76     pic->clear();
  77
  78     delete pic;
  79   }
  80
  81
  82 int main()
  83 {
  84   Check_Container<std::deque<int, clear_alloc<int> > >();
  85   return 0;
  86 }
  87