may be we should use SmartSet in Moose instead of OrderedCollection? Is there any plans for that. I would be in favor.
You mean for all multivalued things (which are not keyed)? I guess this would not work for all arbitrary metamodels; which might depend on the location of elements; and the amount of occurrences?
Btw, I put an implementation of my opposites in the VW implementation of Fame. The implementation can be found under Fame-Slots, and is used in the definition of the FM3 classes. I'm working on porting all my Python-Fame stuff to VW now.
cheers