Two reasons not to use _id2ref:
1) It's slow on other ruby implementations
2) It introduces a hidden bug because _id2ref can return any random
future object since object ids are recycled
Eliminate usage of ObjectSpace._id2ref
I think the BoundObjects will need to be cleared in RR.reset.
I was under the assumption there would have been no bug since there was still a reference to the object (thus the object_id would not have changed) until RR.reset was called. Now I'm curious, is that correct?
But yeah, it makes sense to keep a separate hash if it's going to be slow.
I didn't see where there would be an object referenced until RR.reset, so I dunno. But thats another good reason to not use #_id2ref, namely that there is a hidden behavior here that is very easy to miss and potentially screw up.