Re: [boost] Re: shared_ptr: unsafe, or am I crazy?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-01-21 08:15:02

From: "Larry Evans" <jcampbell3_at_[hidden]>
> Greg Colvin wrote:
>
> > From: "Larry Evans" <jcampbell3_at_[hidden]>
> > > ...  Could someone
> > > describe a case where this is not so, i.e. the user does not know what
> > > the most derived class is when creating a shared_ptr<T>?
> >
> > When using a factory function that returns only a pointer to base?
> >
>
> If you mean using the shared_ptr(T*) CTOR, then this is similar
> to Maeder's example and, as pointed out in
>     http://groups.yahoo.com/group/boost/message/23341
> and the user is responsible for avoiding this.

I suppose Greg meant

shared_ptr<Base> createObject(std::string classId);

or something similar.

The main advantage of the 'enhanced' shared_ptr<> is that the author of
createObject() may change the function to return pointers with a custom
deallocator without changing the library interface.

--
Peter Dimov
Multi Media Ltd.