Re: Q: Endless loop by dispatching

[tmoran@acm.org]

> >   What was programmer of Root trying to accomplish when he said
> >
> >>  type Root_Type is tagged private;
>
> He was trying to demonstrate an obscure point
 ;)
But to rephrase the question: Why would an application programmer write
  type Root_Type is tagged private;
instead of
  type Root_Type is new Ada.Finalization.Controlled with private;
unless he specifically did not want derived types to do their own
Initialize et al.  As I understand:
>     -- derived type is known to be tagged but not controlled.
>     procedure Initialize (Object : in out Derived_Type); -- 2
>     ...
>        Obj : Leaf.Derived_Type; -- Which Initialize gets called?
>   Leaf.Initialize Called.
>
> At least GNAT agrees with me. ;-)
you and Gnat believe that
  type Root_Type is tagged private;
  type Root_Type is new Ada.Finalization.Controlled with private;
should be equivalent, right?  It seems to me that additional ways to
say the same thing are of modest value, while ways to say something
different are of greater value, so I would want those two declarations
to accomplish different, not the same, things.