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

From: Peter Dimov (pdimov_at_[hidden])
Date: 2001-07-24 08:04:17

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.

--
Peter Dimov
Multi Media Ltd.