Re: [Boost-Users] Is intrusive_ptr the thing to use?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-11-27 07:03:59

From: "Hickman, Greg" <greg.hickman_at_[hidden]>
> > From: Peter Dimov [mailto:pdimov_at_[hidden]]
> > If 'f' is virtual, have the object store a weak_ptr to itself:
> >
> > class X
> > {
> > private:
> >
> >     weak_ptr<X> weak_this;
> >
> >     X();
> >     X(X const &);
> >     X& operator=(X const &);
> >
> > public:
> >
> >     static shared_ptr<X> create()
> >     {
> >         shared_ptr<X> px(new X);
> >         px->weak_this = px;
> >         return px;
> >     }
>
> I must be missing something here, because it appears as though you can't
> derive a Y from X and still initialize X::weak_this.

You could simply make X::weak_this and X::X() protected... although if you
follow the design rule that says that non-leaf classes should be abstract
(and if possible contain no data) this shouldn't be necessary, as X as
pictured above would be a leaf.