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From: ytomino <aghia05@gmail.com>
Newsgroups: comp.lang.ada
Subject: Re: discriminant questions
Date: Sun, 18 Sep 2011 05:41:24 -0700 (PDT)
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Date: 2011-09-18T05:41:24-07:00
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> 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.
Yes.

> Ada does not allow this, unfortunately.
OK.
...If I remove assignment operation like unique_ptr of C++0x, it's
possible.

> My position is that interfaces of all types must be inheritable and
> implementable, including access types, but most people here disagree with
> me.
I agree with you. I want to make multi-precision Big_Integer, more
usable Unbounded_String, etc, too.

> 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 it hides semantics of access type,
Ada.Containers.Indefinite_Holders gives good interface.
(if reference-counted implementation is provided.
but http://gcc.gnu.org/svn/gcc/trunk/gcc/ada/a-coinho.adb is not.)