The logical conclusion is that java.lang.Object is a parametric class with a
parameter saying if it should implement IdentityObject or not.
Magic hammer, meet nail :)
To be explicit, what you're suggesting is something like
class Object<ID : boolean> { ... }
where an identity class extends Object<true> and a primitive class
extends Object<false> (and most interfaces remain parametric in ID.)
Its conceptually elegant, and we've discussed it before; in theory
parametricity could range over things other than types, such as
constants, identity-ness, etc (e.g., the ref and val projections could
be species). But to apply it to a problem as prosaic as this seems like
cracking a walnut with a two-ton bomb. (I don't thing this is what you
want to teach on day 1.)
