[plt-scheme] MysterX and ImageMagick COM object

From: Paul Steckler (steck at stecksoft.com)
Date: Thu Jul 24 14:19:10 EDT 2003

> I agree that it may not be necessary to avoid using a direct 
> call, but it looks as though it would require quite a bit 
> more rearranging of MysterX to make it work this way - the 
> type checking MysterX does on a direct call doesn't handle 
> vararg functions.

Sure.  I think this should be added in full generality.  Now, 
who's gonna code that up? :-)

> In addition, I'm not sure that the vararg calling convention 
> works with a direct call.  See below.

I assume that packaging the args into a SAFEARRAY, then 
pushing its address works with C.  Or is the IDL a complete 
smokescreen for reality?

> The very last paragraph sheds some light on this: ...

I think this quote supports the idea that the server actually does 
expect a SAFEARRAY.  IDispatch::Invoke() builds the SAFEARRAY for 
you, if you're using Automation; otherwise, you have roll your own.

-- Paul

Posted on the users mailing list.