> On Apr 14, 2016, at 5:51 PM, Tony Whyman <[email protected]>
> wrote:
>
> unit unitA;
>
> interface
>
> type
>
> class TClassA
> private
> FClassBObject: TObject;
> public
> procedure SomeProc;
> end;
>
> implementation
>
> uses unitB;
>
> Maybe I’m doing something stupid but other languages have forward
> declarations so I wonder why Pascal isn’t doing this also since it seems like
> the obvious solution.
>
>
> procedure TClassA.SomeProc;
> begin
> TClassB(FClassBObject).OtherProc;
> end;
>
> end.
>
> unitB is pretty similar.
>
> As long as you make sure that FClassBObject really is a TClassB object when
> it is assigned, the above should all work. The only extra effort is with the
> TClassB(...) wrapper for each reference to FClassBObject.
I use forward declarations sometimes but of course they need to be in the same
block so they don’t solve this problem.
Yeah type casting. :) Like interfaces they work but they add a significant
overhead and clutter (especially if they need to be used with dozens of methods
in a unit) so that’s why I’m seeing if there’s a better way. However I think I
like your idea of using them in conjunction with the uses in the implementation
instead of my "abstract class" solution. Thanks for the tip.
Regards,
Ryan Joseph
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