From: Jean-Hugues ROBERT <jean_hugues_robert@...>
Date: 2004-04-08T05:15:00+09:00
Subject: IdentityHash, like Hash but with keys using equals? vs eql?



Hi,

I just encountered a rare case where I need a Hash where keys
are object id. Class Hash compares keys by value. As a result
two different String with the same value are considered the
same key. This is fine in most cases. But right now I need to
be more restrictive and I need two String objects to be treated
as two keys even if they have the same value.

I think IdentityHash is a probable name for such a beast, yet
I could not find one in Ruby and I don't see any method in
class Hash that I could redefine in a derived class to change
the way keys are compared.

BTW: IdentityHash should be slightly faster than Hash.

Any clue ?

Thanks,

Jean-Hugues Robert