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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: discriminant questions
Date: Sun, 18 Sep 2011 13:35:47 +0200
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Date: 2011-09-18T13:35:47+02:00
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On Sun, 18 Sep 2011 03:54:48 -0700 (PDT), ytomino wrote:

>> If you mean specifically overriding the "operation" X.all, no you cannot.
> 
> I would like to make record look like access type, not dereferenced
> value.

That is. You want to implement the interface of an access type (X.all is a
part of this interface) by a type which is not access. Ada does not allow
this, unfortunately.

My position is that interfaces of all types must be inheritable and
implementable, including access types, but most people here disagree with
me.

> If we can replace P.Element.all.all to P.all, that is good enough.
> (type of P.Element is access access target-type)
> ".all" is applied to raw access value on my plan.
> Probably it's not related that you are worried.

But you can have P.Element which is much more comfortable. There is no
reason to expose access semantics if you can avoid it. And smart pointers
are to hide pointers rather than to expose them.

> If you insist, my purpose is trying new feature which seems to be
> interesting.

I am not sure if Ada 2012 offers new features interesting for designers of
container libraries. OK, maybe one, functions have finally got [in] out
parameters.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de