[boost] Re: Re: Re: Re: Intrusive smart pointer

From: Fernando Cacciola (fcacciola_at_[hidden])
Date: 2002-04-19 16:21:24

"Peter Dimov" <pdimov_at_[hidden]> wrote in message
news:01b101c1e7e2$c057f6e0$1d00a8c0_at_pdimov2...
> From: "Fernando Cacciola" <fcacciola_at_[hidden]>
> >  int main()
> > {
> >   boost::intrusive_ptr<X> px(new X);  // obj's internal count=1
> >   boost::intrusive_ptr<X> px2(px); // obj's internal count=2
> >   boost::shared_ptr<X> px3(px2); // obj's internal count still =2,
> detached
> > count=1
> >
> >   px = 0; // obj's internal count=1
> >   px2 = 0; // obj's internal count=0  -----> obj suicides itself....
> >
> > *px3 ;  // undefined behavior, pointee no longer alive.
> >  }
> >
> > What I am missing?
>
> Try it. :-)
>
OK. I thought that you have *only* added intrusive_ptr<>, but you have
actually changed both shared_ptr<> and shared_count<>.

I'm still not so sure if we really *need* both shared_ptr<> and
intrusive_ptr<>.

Anyway, this appears to work very seamlessly.

--
Fernando Cacciola
Sierra s.r.l.
fcacciola_at_[hidden]
www.gosierra.com