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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Inherited Methods and such
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Date: Sun, 30 Sep 2007 10:38:02 +0200
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Date: 2007-09-30T10:38:02+02:00
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On Sat, 29 Sep 2007 19:39:47 -0400, Robert A Duff wrote:

> One limitation of my example: it doesn't work if the parent
> type is abstract.  In a from-scratch language design, I think
> I would solve that problem by allowing the creation of objects
> of abstract type. And constructor functions returns such
> objects.  But don't allow conversion of such objects to
> class-wide (to avoid dispatching (to abstract subprograms)).
> What do you think about that?  It's not Ada, of course.

The black hole of copying non-copyable, returning already existing into
itself, now, creating impossible is swallowing the language. (:-))

I think that a construction model of
constraint->implementation->unconstrained-thing is semantically cleaner and
can work for all types.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de