Re: Suggestion: Allow functions returning abstract types in certain situations

[Adam Beneschan <adambeneschan@gmail.com>]

On Wednesday, May 21, 2014 3:04:05 PM UTC-7, Robert A Duff wrote:
> Adam Beneschan writes:

> >...In my view, the language model depends heavily on
> > the assumption that an object can never be created whose tag refers to
> > an abstract type; allowing the rule to *ever* be relaxed could be
> > disastrous.
> 
> I don't think so.  As I posted a while back, the only trouble comes
> from converting an object of an abstract type to a class-wide
> type -- that is what needs to be forbidden.

Hmmm... I'd worry that if we allowed an object with an abstract-type tag to exist even for a little while, something in the language semantics might require Initialize, Adjust, or Finalize to be called on it, which could be bad if, for example, it tried to redispatch to an abstract body.  (I don't remember the earlier conversation, so I don't know if this was dealt with already.)

                                  -- Adam