> > More precisely if the hash of the key changes the bucket changes.  And
> > since Array calculates it's hash based on the content changing the
> > content means changing the key.  And, to the OP, lookups in Hashes are
> > not done via #object_id but via #hash:
> >http://en.wikipedia.org/wiki/Hashtable
>
> which all is necessary in order to have mutable keys, I guess that it
> is very difficult to think about that in the beginning when not yet
> used to it.

I understand now.  I can see how looking up keys by their hash rather
than their object_id is more appropriate.

> BTW. I try to avoid to mutate hash keys, I know my limits ;)

Agreed.  I was just curious about how things worked underneath.

Thanks for all the responses.

-DK