[D.typesystem] Suggestion for improving OO inheritance models

[Justin Johansson]

Whilst one admirable aspiration of D is to make for better
meta-programming capability in a PL, IMHO one seemingly-lacking
aspiration of D is in the area of improving OO inheritance models
over and above that provisioned for in C++ and Java.

Maybe I'm ill-informed though I'd say that D, C++ and Java
more-or-less share the same OO inheritance model being that
of inheritance/derivation by extension as opposed to, say,
inheritance/derivation by restriction.  (Observation: Java
even uses the 'extends' keyword to introduce derived classes;
this hardly caters for inheritance by restriction).

May I suggest that a discussion ensure about a taxonomy of
OO inheritance models, including the notions of inheritance
by extension, restriction, code refactoring purposes etc.
so that D can evolve to a position to be able to claim a
higher moral plane over C++, Java, et al.

Cheers
Justin Johansson