Re: problem with poseAs

[Fred Kiefer]

Lloyd Dupont wrote:
> I'm trying to port an application write on MacoSX to GNUstep/Windows.
> The application uses many MacOSX 10.3 features (I mean method and 
> classes added in 10.3).
>
> I had a runtime error because of such a missing accessor for a new 
> defaultTabInterval property in NSMutableParagraphStyle.
>
> So I decided to simply write a superclass and use the 'poseAs ' mechanism.
> However, when I did so, I had this puzzling error message issued by the 
> runtime (and followed by an exit(3)):
> Assertion failed: impostor->instance_size == super_class->instance_size, 
> file class.c, line 638
>
> I'm kind of puzzled, couldn't you have new instance variable in a posing 
> subclass?
> That's the whole advantage compare to categories...
>
> How could I work around that?
> I need paragraph style information extensoively and absolutely, I can't 
> simply remove the code using it....

If you need this additional behaviour that badly, why not just write the 
code and donate it to GNUstep? Getting it somehow working in your 
private application may be great for you, but having it in GNUstep will 
benefit all of us.
That is one of the benefits of free software, you have the code 
available and are able to change it.
Write a patch that includes your additions and sign a copyright 
assignment to the FSF, thats it. If you send the patch this weekend, I 
promisse to include it into CVS until Sunday. I wont have time to do 
this next week, but others may.

Cheers
Fred