Re: Specialization

[Simon Wright <simon@pushface.org>]

Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov> writes:

> One more: require the client to pass in a Finalize procedure:
> 
> generic
>    type Element is private;
>    with procedure Finalize (Item : in out Element) is <>;
> package Foo is
>    type Element_array is array (1 .. 10) of Element;
> 
>    procedure Empty (Item : in out Element_Array);
> 
> end Foo;
> 
> Now Empty can call Finalize on each element of the array. For
> non-controlled types, Finalize can be a null operation. This is the
> approach I use in SAL; it allows a generic package to be
> instantiated with the widest range of types.

I like this.

The Element probably has to be visibly (to the client) controlled, for
her to get hold of the Finalize.