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: 103376,6339fea48a1b8cda
X-Google-Attributes: gid103376,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news1.google.com!postnews.google.com!f36g2000hsa.googlegroups.com!not-for-mail
From: Adam Beneschan <adam@irvine.com>
Newsgroups: comp.lang.ada
Subject: Re: Enumeration representation clause surprise.
Date: Thu, 12 Jun 2008 15:42:29 -0700 (PDT)
Organization: http://groups.google.com
Message-ID: 
 <a8383f62-0152-41c7-a4aa-ecb640a69234@f36g2000hsa.googlegroups.com>
References: <g2odf9$3um$1@nntp.ilk.net>
 <770ae1af-b9fd-4c8a-915c-a5cb3ea8fc81@c65g2000hsa.googlegroups.com>
	<87hcbybazk.fsf@willow.rfc1149.net>
NNTP-Posting-Host: 66.126.103.122
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-Trace: posting.google.com 1213310549 9404 127.0.0.1 (12 Jun 2008 22:42:29
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Thu, 12 Jun 2008 22:42:29 +0000 (UTC)
Complaints-To: groups-abuse@google.com
Injection-Info: f36g2000hsa.googlegroups.com; posting-host=66.126.103.122;
	posting-account=duW0ogkAAABjRdnxgLGXDfna0Gc6XqmQ
User-Agent: G2/1.0
X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.7.12)
	Gecko/20050922 Fedora/1.7.12-1.3.1,gzip(gfe),gzip(gfe)
Xref: g2news1.google.com comp.lang.ada:681
Date: 2008-06-12T15:42:29-07:00
List-Id: <comp.lang.ada>

On Jun 12, 2:26 pm, Samuel Tardieu <s...@rfc1149.net> wrote:
> > Interesting. I had been playing with a similar example, and have
> > modified it a bit to present. What got me is the record type with
> > length 1 but an object with that type that was length zero!
>
> The only possible value for X_Type is X. This requires 0 bit of
> information to represent this fact.
>
> > (It compiles without any warnings).
>
> With the proposed patch, it gives:
>
> GNAT 4.4.0 20080611 (experimental)
> Copyright 1992-2008, Free Software Foundation, Inc.
>
> Compiling: test1.adb (source file time stamp: 2008-06-12 21:22:24)
>
>     26.         X1 at 0 range 0 .. -1;                   -- Minus 1 !!
>                    |
>         >>> warning: component representation will be biased

So what would the value of the bias be?

                            -- Adam