From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,8982dc345b43855
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news3.google.com!news2.volia.net!zen.net.uk!dedekind.zen.co.uk!news-peer-lilac.gradwell.net!not-for-mail
From: "Martin Dowie" <martin.dowie@baesystems.com>
Newsgroups: comp.lang.ada
References: <dm41j1$epv$1@sunnews.cern.ch>
Subject: Re: Uninitialized variable and the effects they have
Date: Thu, 24 Nov 2005 11:49:50 -0000
Organization: BAE SYSTEMS
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2800.1506
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1506
Message-ID: <4385a6e7$1_1@glkas0286.greenlnk.net>
X-Original-NNTP-Posting-Host: glkas0286.greenlnk.net
NNTP-Posting-Date: 24 Nov 2005 11:51:09 GMT
NNTP-Posting-Host: 20.133.0.1
X-Trace: 1132833069 news.gradwell.net 38044 dnews/20.133.0.1
X-Complaints-To: news-abuse@gradwell.net
Xref: g2news1.google.com comp.lang.ada:6584
Date: 2005-11-24T11:51:09+00:00
List-Id: <comp.lang.ada>

Maciej Sobczak wrote:
[snip]
> I : Integer; -- uninitialized

It's likely that "I" will contain a valid value - you just don't know what
it is! If it was a float it might be a different matter.


> J : Integer := I + 2;

The assignment may raise a Constraint_Error depending on what happened to be
in I at the time.

That's (yet another) reason to declare your own types and preferably ones
that are not full range with respect to their base type. Combine that with
"pragme Normalize_Scalars;" (see H.1) and you have a chance.

In general, see 13.9.1.

Cheers

-- Martin