RE: [GD-General] Multiple Inheritance and RTTI

[Donavon K. <kei...@ea...>]

This is one of those times where I wish I'd looked more carefully at
what I wrote before sending it.  My comments sound pretty uncharitable
but this company has a lot of talented people who have done some really
great stuff.  I'm sure some people here know which company this is and
may even be working there, so if I stepped on any toes, I regret it.

--Charm School Dropout

> -----Original Message-----
> From: gam...@li...
> [mailto:gam...@li...] On Behalf Of
> Donavon Keithley
> Sent: Saturday, February 08, 2003 12:28 AM
> To: gam...@li...
> Subject: RE: [GD-General] Multiple Inheritance and RTTI
> 
> Instantiating a class by some means other than CoCreateInstance[Ex] is
> not re-implementing COM.  Many, many standard COM objects are not
> co-creatable (if I remember the jargon correctly).  Like... D3D, for
> instance.
> 
> COM only has a few mandatory rules, like implementing IUnknown and
> adhering to certain QueryInterface semantics.  It's not much of an
> imposition and it leaves you open to interoperating with the rest of
the
> COM world.  Implement a typelib and adhere to some basic type rules
and
> your objects will be callable from Visual Basic and .NET.  Implement
> IDispatch and you open your objects up to the scripting world.
> 
> Just don't do what one company I know did, and that's redefine
IUnknown.
> They called it "IUnknown", it had QI, AddRef, and Release, but IIDs
were
> strings, not GUIDs.  So their "custom" COM system looked just like
COM,
> but it was totally incompatible.  There was no possibility of interop
> and where they could have taken advantage of ATL's rich set of
classes,
> they instead had to redefine their own macros and template classes.
> 
> It was an utterly pointless exercise in NIH.
> 
> Donavon