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

[Adam Beneschan <adambeneschan@gmail.com>]

On Wednesday, May 21, 2014 4:19:21 PM UTC-7, Robert A Duff wrote:

> Not sure what you mean about "redispatch".  You can't [re]dispatch
> without converting to class-wide.

It didn't occur to me until later that your idea about forbidding a conversion from an abstract type to a class-wide type has to be a run-time check, not a compile-time check (or not solely a compile-time check).  Otherwise, if an operation of a concrete type converts a controlling parameter to a class-wide type, and then an abstract type is derived without overriding the operation, the code would then be converting the abstract object to a class-wide type unless it were checked at run-time.

That's the sort of scenario I was thinking of when I mentioned Initialize/Adjust/Finalize doing a redispatch.

                               -- Adam