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From: "Nick Roberts" <Nick.Roberts@dial.pipex.com>
Subject: Re: AQ&S Guidance on pragma Elaborate_Body
Date: 1997/04/26
Message-ID: <01bc5250$db1b6c00$28f982c1@xhv46.dial.pipex.com>#1/1
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References: <528878564wnr@diphi.demon.co.uk> <dewar.861414695@merv>
 <5jabeq$3ltk@info4.rus.uni-stuttgart.de> <5jfukp$lda@top.mitre.org>
 <dewar.861816859@merv> <mheaney-ya023680002404970907100001@news.ni.net>
 <JSA.97Apr24162056@alexandria>
 <mheaney-ya023680002404972329250001@news.ni.net>
Organization: UUNet PIPEX server (post doesn't reflect views of UUNet PIPEX)
Newsgroups: comp.lang.ada
Date: 1997-04-26T00:00:00+00:00
List-Id: <comp.lang.ada>




Matthew Heaney <mheaney@ni.net> wrote in article
<mheaney-ya023680002404972329250001@news.ni.net>...
> Knowing that tagged types are passed by reference, perhaps we could avoid
a
> spec dependency on the package containing a tagged type's declaration:
> 
> with Q.T is tagged limited private;
> package P is
> 
>    type S is private;
> 
>    procedure Op (OS : in out S; OT : in Q.T);  -- OT is passed by
reference
> ...


It's a nice idea. The problem with this idea, though (I think), is that
there are no operations defined for Q.T for use in the body of procedure
Op. What is Op able to do with the parameter OT? Anything?

Nick.



PS: If we had

with Q.T is abstract tagged limited private;

we could then derive from Q.T, add our own operations, and then use those
operations (only). But would this ever be useful?