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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Ada 'hello world' for Android; success!
Date: Tue, 1 Nov 2011 10:52:08 +0100
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Date: 2011-11-01T10:52:08+01:00
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On Sun, 30 Oct 2011 07:32:59 -0400, Stephen Leake wrote:

> In brief, _any_ framework that uses dispatching on class-wide
> objects needs reference semantics.

Wrong. Reference semantics is required to maintain object's identity.
Without identity there is no need in it. This is unrelated to being
class-wide which requires *type identity* rather than the object's one. You
could have any combination of those two. One of the key advantages of Ada's
OO model is that it decouples them.

> In Ada, that is indicated by the explicit word 'access'.

Possibly yes, though tagged types are by-reference anyway. Actually
"limited" is the indicator for object's identity. What about freshly
introduced by Ada 2012 "aliased"?

BTW, Consider an architecture where the object address may change, while
keeping its identity. Thin pointers won't work for such "wandering"
objects...

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