Question on layer/peeling

[Michael Barker]

>
> I suppose the workaround for #3 would be to take a Hasher<T> (or whatever
> name you pick) instance as a ctor arg; this would provide equals/hashCode
> for your type T.
>
Cheers, this worked.  I now have a working specialised HashMap[1].  When
some of the "implementation by parts" makes an appearance, I'll rework to
see if I can remove the custom Hashers.

[1] modulo null problems mentioned earlier and not implementing some of the
j.u.Map methods, e.g. keySet(), entrySet().