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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Ada Alternatives to Unrestricted_Access
Date: Mon, 12 Mar 2018 17:28:03 +0100
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Xref: reader02.eternal-september.org comp.lang.ada:50938
Date: 2018-03-12T17:28:03+01:00
List-Id: <comp.lang.ada>

On 03/11/2018 08:53 PM, Jere wrote:
> 
> procedure Debug_Print(C : Container) is
> begin
>     for E of C loop
>        Ada.Text_IO.Put_Line(Element'Image(E));
>     end loop;
> end Debug_Print;
> 
> procedure Nefarious(C : in out Container) is
> begin
>     for E of C loop
>        if E = Some_Value then
>           <do some stuff>
>           C.Delete(E);  -- tamper check!
>     end loop;
> end Nefarious;

If you can't do both with standard, checked programming, then user-defined 
iteration is broken.

> It's all pre-existing code.  I don't want to add anything.  The
> iteration was already there.  The owner asked to see if I could
> get rid of some GNAT specific extensions easily.
> One was the use of Unrestricted_Access, which led me to the original
> question.  They didn't want a major overhaul of the code.

Address-to-access conversions should be correct and portable, but 
'Unrestricted_Access is probably clearer.

-- 
Jeff Carter
"We'll make Rock Ridge think it's a chicken
that got caught in a tractor's nuts!"
Blazing Saddles
87