From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: null exclusion and generics
Date: Fri, 20 Oct 2006 09:57:41 +0200
Date: 2006-10-20T09:57:41+02:00 [thread overview]
Message-ID: <rzi6fg9dvwkj$.1sgq0u8z632e4.dlg@40tude.net> (raw)
In-Reply-To: reSdnSjHmLyTRqrYnZ2dnUVZ_qadnZ2d@megapath.net
On Thu, 19 Oct 2006 15:08:17 -0500, Randy Brukardt wrote:
> So all access types are initialized with null, and if the subtype is
> null-excluding, that will automatically raise Constraint_Error. A null
> exclusion is essentially a kind of constraint (it is not technically a
> constraint, but that has to do with independence from other forms of
> constraint). Think of it being like:
>
> subtype A is Integer range 1 .. 10;
>
> Obj : A := Integer'First;
>
> which also will raise C_E. (If we had allowed a way to declare automatic
> initializations for scalar types -- something I wish we had done -- it would
> have had a similar effect as the explicit initialization here).
This is one more reason to finally introduce a sane
construction/destruction model in Ada. Compromises never buy off.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
prev parent reply other threads:[~2006-10-20 7:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-19 12:51 null exclusion and generics Georg Bauhaus
2006-10-19 13:06 ` Dmitry A. Kazakov
2006-10-19 20:08 ` Randy Brukardt
2006-10-20 7:57 ` Dmitry A. Kazakov [this message]
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