Re: generic formal object of class-wide type

["Jean-Pierre Rosen" <rosen.adalog@wanadoo.fr>]

Matthew Heaney a �crit dans le message ...
>When I try to compile package Q (see below), I get this error:
>
>q.ads:3:25: type of actual does not match type of "O"
>
>Why?
>
>Generic formal object O (in GQ) is of type P.T'Class.
>
>Actual object O is of specific type NT, yes, but that type is in
>T'Class.  So why isn't object O allowed as the actual for formal
GC.O?
>
If the formal is declared as P.T'Class, the actual has to be P.T'Class
(P.T'Class IS a type that follows (mostly) usual typing rules).
If you want to allow for a type IN the class, you say that it is
derived from P.T:

generic
   type D is new P.T with private;
---------------------------------------------------------
           J-P. Rosen (Rosen.Adalog@wanadoo.fr)
Visit Adalog's web site at http://perso.wanadoo.fr/adalog