Re: Invoking abstract subprograms in Ada95

[michael.jackson5@virgin.net (Mike)]

"Grein, Christoph" <christoph.grein@eurocopter.com> wrote in message news:<mailman.1019483282.562.comp.lang.ada@ada.eu.org>...

> Class-wide operations cannot be abstract, they also cannot be overrridden.
> 
> OK, they can be abstract, this is why your code compiles, but abstractness here 
> has a devastating meaning: There can never be such an operation!


Aha. Now I see the error of my ways.

> 
> 
> > end abstract_bit;
> > 
> > --
> > package body abstract_bit is
> > 
> > procedure generalOperation( this : in out A'class ) is
> > begin
> >     specificOperation( this => this );
> 
> You said it was abstract, so does not exist! Therefore you cannot call it here.

Weeell in my mind, for generalOperation to be invoked, 'A' must have
been extended sufficiently to be non abstract, and therefore an
implementation of specificOperation *must* exist ;)

Thanks for the help!

Mike