IDL interfaces

[Jonathan S. Shapiro]

> The "thins" relationship is the inverse of the "extends" or "inherits
> from" relationship.  The more powerful interface is simply a subclass
> of the less powerful interface.

This is often, but not always true.

> Typically, statically-typed OO systems provide a way to get the
> subclass interface given the superclass interface to an object of a
> subclass.  At least, C++ and Java do.  I don't know about Eiffel.  We
> don't want this feature.

Indeed! The ability to convert an interface pointer back to it's originating
object pointer in Java is one of the single biggest design flaws in the
language. The synchronization design is worse, of course, but this is way
the heck up there.

shap