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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: discriminant questions
Date: Thu, 22 Sep 2011 10:11:55 +0200
Organization: cbb software GmbH
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Date: 2011-09-22T10:11:55+02:00
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On Wed, 21 Sep 2011 21:52:47 -0500, Randy Brukardt wrote:

> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
> news:1tpl2pc36ptr4$.txv4v3wmkjlm.dlg@40tude.net...
> ...
>>> Nobody is forcing referential semantics, although it might be the most
>>> natural and efficient solution for iterators.
>>
>> Of course it does, because the iterator refers to the container and to an
>> element in that container. Which is evidently fragile as any reference 
>> when the container and its element mutate.
> 
> Fragile perhaps, but it is definitely possible to be safe (which is more 
> important, IMHO). Ada.Containers are safe in this aspect, as any attempt to 
> mutate the container ("tampering") is required to raise Program_Error. 

Well, but iterators are especially interesting for mutating container due
to their referential semantics. Killing that also does one of key
advantages they, as pointers, have.

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