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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Question about out parameters of unconstrained array type.
Date: Sat, 25 Feb 2012 16:33:08 +0100
Date: 2012-02-25T16:33:08+01:00	[thread overview]
Message-ID: <ovox7uzc45of.1i424y4a6c4v5.dlg@40tude.net> (raw)
In-Reply-To: I8qdndMrnK9zZtXS4p2dnAA@giganews.com

On Sat, 25 Feb 2012 10:19:02 -0500, Peter C. Chapin wrote:

> Consider a simple procedure
> 
> procedure P(S : out String) is
> begin
>     ...
> end P;
> 
> Despite the fact that S behaves as if it is uninitialized my Ada 
> compiler (GNAT GPL 2011) allows me to read certain attributes.

Uninitialized /= not constructed

> Is it well defined?

Yes, because the actual of S has all attributes set. Compare it with this:

declare
   S : String (1..20); -- S is uninitialized, but constructed
begin
   if S'Length > 0 then -- This is OK
 
> Where does it say so?

I don't know, but there is common sense: Ada's design is sane enough not to
allow existence of indefinite objects.

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



  reply	other threads:[~2012-02-25 15:33 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-25 15:19 Question about out parameters of unconstrained array type Peter C. Chapin
2012-02-25 15:33 ` Dmitry A. Kazakov [this message]
2012-02-25 18:20 ` Phil Thornley
2012-02-25 20:01   ` Simon Wright
2012-02-25 22:44     ` Phil Thornley
2012-02-27 13:48       ` Mark Lorenzen
2012-02-27 15:32         ` Phil Thornley
2012-02-25 23:37   ` Alexander Senier
2012-02-26  1:16   ` Peter C. Chapin
2012-02-26  9:14     ` Phil Thornley
2012-02-26 12:25       ` Alexander Senier
2012-02-26 13:20         ` Phil Thornley
2012-02-26 14:25         ` Niklas Holsti
2012-02-26 17:32         ` Jeffrey Carter
2012-02-26 15:29       ` Peter C. Chapin
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