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From: jsa@alexandria (Jon S Anthony)
Subject: Re: Extending A Generic Signature Package
Date: 1997/03/21
Message-ID: <JSA.97Mar21135016@alexandria>#1/1
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References: <5gkv23INN3rn@thalamus.cis.ohio-state.edu>
Organization: PSI Public Usenet Link
Newsgroups: comp.lang.ada
Date: 1997-03-21T00:00:00+00:00
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In article <5gtvbv$1nj@pandora.cs.utwente.nl> boschg@cs.utwente.nl (Geert Bosch) writes:

> Dispatching occurs when you use (pointers to) class-wide types like
> in the following case:
> 
>    declare
>        type Object_Ptr is access all Base'Class;
>       X : Object_Ptr := new Base;
>    begin
>       Op1 (X.all);
>    end;

Just to be clear, "pointers" are only indirectly relevant to
dispatching.  The key is passing a class wide type argument(s) to a
controlling operand(s) of a primitive operation.  For example, there
is no need of a pointer in your above example:

    declare
       X : Base'Class := Get_Object;
    begin
       Op1(X);
    end;

/Jon
-- 
Jon Anthony
Organon Motives, Inc.
Belmont, MA 02178
617.484.3383
jsa@organon.com