Re: [boost] Re: downcasting smart pointers (suggested code)

From: Greg Colvin (gcolvin_at_[hidden])
Date: 2001-07-24 10:34:19

From: Peter Dimov <pdimov_at_[hidden]>
> From: <greg_at_[hidden]>
> > This looks like a good start, thanks.  I think do_dynamic_cast is the
> > name we previously agreed on for your shared_dynamic_cast, and that
> > we wanted a version that worked for raw pointers as well.
> 
> If do_dynamic_cast is supposed to be a generalization of dynamic_cast:
> 
> template<class R, class T> R do_dynamic_cast(T /* const */ &);
> 
> (dynamic_cast<U*> returns U*, dynamic_cast<U&> returns U&)
> 
> then dynamic-casting a shared_ptr would look like
> 
> do_dynamic_cast<shared_ptr<X> >(y); // 1
> 
> whereas with a shared_ptr-specific cast the syntax would be
> 
> shared_dynamic_cast<X>(y); // 2
> 
> I prefer (2). (1) is more generic but I can't see how the genericity would
> be exploited.

It could be exploited in generic code that didn't care whether
it was operating on raw pointers or smart pointers?