Subj : 'Subclassing' JSClass
To   : netscape.public.mozilla.jseng
From : James Turner <james.turner@crocodile-clips.com>
Date : Fri Jan 17 2003 09:54 am

So, in my ongoing path to SpiderMonkey enlightenment..

I need to associate some extra data with each JSClass* . My options are) 
a lookup table based on the pointer value (yuck), stashing a pointer in 
the reserved field of JSClass (liable to break in the future and won't 
work if sizeof(void*) > sizeof(jsword), which I'm guessing it may be on 
64-bit archs )..

Or finally, option c)

	struct {
		JSClass inner;

		// my extra data ...

} 	} ExtendedJSClass;

And pass these around to JS_InitClass and friends. Now, obviously I'm 
currently favoring this last options, so I need to know: is there a 
better way, and/or is anything likely to break with this method? Eg 
internal dense arrays of JSClass structs, etc. It seems unlikely from 
looking at code but I'd like to make sure.

Thanks,
James

.