Re: Extending discriminant types

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Georg Bauhaus <rm.dash-bauhaus@futureapps.de> writes:

> Just out of curiosity, given
>
>    type T is tagged ...;
>    type D is new T with ...;
>    type E is new D with ...;
>
> what would E'Base be?

There seems to be some confusion between "base subtype"
and "parent type".

E'Base is illegal in Ada 95 and Ada 2005.  If it were legal, I suppose
it would be the same as E, since for scalar types, X'Base basically
means "X without constraints", and E has no discriminants and hence no
constraints.

I think the original example in this thread confused things by calling
the root type "Base".  It would be better to say "type Root is ..."
in an example like that.

- Bob