Casting from interface type

[Yves Bailly <kafka.fr@laposte.net>]

Hello all,

Please consider this small code :
--8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<---
procedure Proc is
   type I is interface;
   type T is tagged null record;
   type DT is new T and I with null record;

   var_t: T;
   var_tc: T'Class := var_t;

   procedure Conv(p: in I'Class) is
   begin
      if p in T'Class
      then
         var_t := T(p);
         var_tc := T'Class(p);
      end if;
   end Conv;

   var_dt: DT;

begin

   Conv(var_dt);

end Proc;
--8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<---

Using the latest GNAT 2006, I receive the following errors:
proc.adb:14:19: invalid tagged conversion, not compatible with
type "I'Class" defined at line 3
proc.adb:15:21: invalid tagged conversion, not compatible with
type "I'Class" defined at line 3

Please, can someone tell me what am I doing wrong ?

Thanks in advance for your time.

Best regards,

-- 
(o< | Yves Bailly  : http://kafka-fr.net   | -o)
//\ | Linux Dijon  : http://www.coagul.org | //\
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