Re: class wide object in generic package

["Grein, Christoph" <christoph.grein@eurocopter.com>]

> 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?
>
> generic_pac.ads:
> generic
> 	type Object is abstract tagged private;
> 	type Pointer is access all Object'class;
> 	with procedure eval(o : in out Object);

You can instantiate with any procedure that matches the profile, so the worst is 
assumed and Eval is not a primitive operation.

> 	
> 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);

Since Pointer is classwide, this is a dispatching call, but Eval is not 
primitive, so can't be used in a dispatching call.


> 	end use_it;
> end generic_pac;