Re: [allocator.concept] smart pointer clarifications

From:

"Phil Bouchard" <phil@fornux.com>

Newsgroups:

comp.lang.c++,comp.lang.c++.moderated

Date:

Fri, 22 Aug 2008 06:59:29 CST

Message-ID:

<g8lslv$ish$1@aioe.org>

"Phil Bouchard" <phil@fornux.com> wrote in message
news:g8jofb$ust$1@aioe.org...

[...]

Where:
template <typename T>
    virtual allocator_type list_base<T>::get_allocator() const = 0;

And, for example:
template <typename T, typename Alloc>
    virtual allocator_type list<T, Alloc>::get_allocator() const
    {
         return allocator_type(*static_cast<const
_Node_Alloc_type*>(&this->_M_impl));
    }

Sorry here I meant protected functions should be virtual, not
get_allocator():

template <typename T>
     class list_base : public ...
     {
         virtual _List_node<_Tp>* _M_get_node() = 0;
         virtual void _M_put_node(_List_node<_Tp>* __p) = 0;
     };

template <typename T, typename Alloc>
     class list : public list_base<T>
     {
     protected:
        _List_impl _M_impl;

         virtual _List_node<_Tp>* _M_get_node()
         {
             return _M_impl._Node_Alloc_type::allocate(1);
         }

         virtual void _M_put_node(_List_node<_Tp>* __p)
         {
             _M_impl._Node_Alloc_type::deallocate(__p, 1);
         }

     public:
         _Alloc get_allocator() const
         {
             return _Alloc(*static_cast<const
_Node_Alloc_type*>(&this->_M_impl));
         }

         ...
     };

-Phil

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