Re: Interfaces

[Florian Weimer <fw@deneb.enyo.de>]

* Robert A. Duff:

>> Maybe it wouldn't be too complicated to add a way to specify the
>> interface which you are overriding? Something like "overriding J1
>> procedure Foo"?  This would result in an error message if Foo also
>> overrode a subprogram inherited from T or J2.
>
> Maybe.  I'm not sure how this would work with multiple inheritance in
> general.  For example the diamond inheritance pattern.

I'm not after such fancy things.  Basically, I'd like to declare that
there is no diamond, by explicitly labeling the interfaces I'm
overriding.

The compiler has to gather the information anyway, to built the
dispatch tables.  Implementation-wise, it shouldn't be very hard to
check if the subprogram ends up in the specified tables only.