Re: Invoking abstract subprograms in Ada95

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

michael.jackson5@virgin.net (Mike) writes:

> In Ada 95 terms I have a package X that contains abstract type Xt and
> describes some abstract behaviour "procedure Z". I also have Ada95
> Child Package X.Y that contains a non abstract type Yt that extends
> and fully completes Xt.
> 
> Within package X I have a classwide procedure (actually an XWindows
> Callback) that I want to be invoked by all types of child, *but* there
> are some specific tasks that can only be completed by the concrete
> child (Y in this case) that fully implements procedure Z.
> 
> Gnat Ada95 will not let me do this: "Cannot call abstract subprogram"
> 
> * Why can I not invoke procedure Z from with package X?

Apparently you have coded a non-dispatching call. Please post the code.


-- 
-- Stephe