Re: making interface hierarchies

[Owen Taylor <otaylor redhat com>]

On Fri, 2003-09-12 at 11:07, Ronald Bultje wrote:
> Hi,
> 
> I want to make a GInterface hierarchy, where I have a type GstInterface
> that implements some functions to make interfaces on a per-instance
> basis, and some actual interfaces, based on GstInterface.
> 
> However, after having coded quite a bit, I get this error:
> (lt-gst-mixer:29879): GLib-GObject-WARNING **: cannot derive `GstMixer'
> from non-fundamental parent type `GstInterface'
> Which seems to indicate that I can't make multi-derivations of
> GInterface. Why is this, is it fixable (either in glib or - with a
> workaround - in my app), or should I use a different approach?

The closest analogy to inheritance for interfaces is prerequisites.
You can say "Every object that implements GstMixer must also
implement GstInterface".

Regards,
						Owen