Is there a way of creating an IdentityMap in scala 2.8

Question

There used to be an IdentityHashMap in collection.jcl: is there a way of constructing the same thing in the new 2.8 collections library (perhaps with a bespoke equality-relation)?

Answer 1

In scala.collection.mutable.HashMap there are two protected methods, elemEquals and elemHashCode. If you override them you can create an IdentityHashMap of your own.

In scala.collection.immutable.HashMap there is only elemHashCode. (I don't know why, offhand.)