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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Implicit dereferences rational question
Date: Tue, 20 May 2014 09:29:36 +0200
Date: 2014-05-20T09:29:36+02:00	[thread overview]
Message-ID: <1pkkrdwu7lh6y.7cjyncdfw33e.dlg@40tude.net> (raw)
In-Reply-To: llduds$47j$1@loke.gir.dk

On Mon, 19 May 2014 16:51:56 -0500, Randy Brukardt wrote:

> "Victor Porton" <porton@narod.ru> wrote in message 
> news:llb1aa$gth$1@speranza.aioe.org...
>> Robert A Duff wrote:
>>> Victor Porton <porton@narod.ru> writes:
>>>
>>>> Why implicit dereferences use only access discriminants, not arbitrary
>>>> access fields?
>>>
>>> It helps prevent dangling pointers.
>>
>> In which way limiting to discriminants may prevent dangling pointers?
> 
> Discriminants have a lengthy set of accessibility rules, which turn out to 
> be exactly what's needed for limiting dangling pointers. In particular, it's 
> almost never the case that one can make a copy of an access discriminant, 
> while that's easy for a "arbitrary access field".

Except that dereference, be it implicit or explicit, does not create
pointers. Obviously, it eliminates a pointer, as the name suggests.

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


  parent reply	other threads:[~2014-05-20  7:29 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-18 15:24 Implicit dereferences rational question Victor Porton
2014-05-18 17:08 ` Robert A Duff
2014-05-18 19:22   ` Victor Porton
2014-05-19 21:51     ` Randy Brukardt
2014-05-19 22:44       ` Robert A Duff
2014-05-20  7:29       ` Dmitry A. Kazakov [this message]
2014-05-20 21:26         ` Randy Brukardt
2014-05-21  7:36           ` Dmitry A. Kazakov
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