Re: Instantiating ComObjects - best practice

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Sat, 26 Jul 2008 12:45:59 -0400

Message-ID:

<uyXlY8z7IHA.2416@TK2MSFTNGP02.phx.gbl>

"Alexander Lamaison" <newsgroups@lammy.co.uk> wrote in message
news:eL5Xcjz7IHA.3336@TK2MSFTNGP03.phx.gbl

So does this mean that, in a variation on my initial question,
something like this is ok:

IMyInterface *pFace;
hr = CMyObject::MakeInstance( imp-specific stuff );

... <later in program>

static_cast<CMyObject *>(pFace)->SomeImplementationSpecificMethod();

Yes, you could do that. Personally, I'd rather store raw CMyObject*
pointer instead. It's clearer this way what's going on.

Of course, this would only work on an interface pointer that comes
directly from your object. If the pointer is accepted from the client as
input, or it's a pointer marshalled to a different apartment (in which
case it's implemented by a proxy object), it will crash spectacularly.
--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925