class wide object in generic package

[Thomas Maier-Komor <maierkom@rcs.ei.tum.de>]

Hi everybody,

I am getting this error message when compiling the
code at the end of the message:

generic_pac.adb:7:26: class-wide argument not allowed here
generic_pac.adb:7:26: "eval" is not a primitive operation of "Object"


my question is:
first: is it possible to declare a procedure in the
generic part so that it will be a primitive operation of
Object?
second: why isn't a class-wide argument not allowed
in this place?


Thanks,


Tom



generic_pac.ads:
generic
	type Object is abstract tagged private;
	type Pointer is access all Object'class;
	with procedure eval(o : in out Object);
	
package generic_pac is
	type gen is record
		p : Pointer;
	end record;

	procedure use_it(g : in out gen);
	
end generic_pac;
===========================================
generic_pac.adb:
with Ada.Text_IO; use Ada.Text_IO;

package body generic_pac is
	procedure use_it(g : in out gen) is
	begin
		Put_Line("generic_pac.use_it");
		eval(g.p.all);
	end use_it;
end generic_pac;

-- 
________________________________________________________________________
Dipl.-Ing. Thomas Maier-Komor                   http://www.rcs.ei.tum.de
Institute for Real-Time Computer Systems (RCS)      fon +49-89-289-23578
Technische Universitaet Muenchen, D-80290 Muenchen  fax +49-89-289-23555