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=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Thread: 103376,b9880ab5a4975a57
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news1.google.com!news.glorb.com!npeer.de.kpn-eurorings.net!border2.nntp.ams.giganews.com!nntp.giganews.com!tiscali!newsfeed1.ip.tiscali.net!feed.news.tiscali.de!newsfeed01.sul.t-online.de!newsmm00.sul.t-online.de!t-online.de!news.t-online.com!not-for-mail
From: Martin Krischik <krischik@users.sourceforge.net>
Newsgroups: comp.lang.ada
Subject: Re: Object with zero bits
Date: Thu, 14 Oct 2004 10:13:09 +0200
Organization: AdaCL
Message-ID: <4730271.U8RaYIMhj8@linux1.krischik.com>
References: <mailman.299.1097648124.390.comp.lang.ada@ada-france.org>
 <5ad0dd8a.0410130718.6a7bd161@posting.google.com>
 <ckjns1$342$1@a1-hrz.uni-duisburg.de>
Reply-To: krischik@users.sourceforge.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7Bit
X-Trace: news.t-online.com 1097742255 02 31508 fxORXepJHi2SSw2p 041014
 08:24:15
X-Complaints-To: usenet-abuse@t-online.de
X-ID: VmSHVvZHQef67H6Za5xtInjRlVjaWQ8bGFebMyZnNNdbyHewfocL0b
User-Agent: KNode/0.8.0
Xref: g2news1.google.com comp.lang.ada:5187
Date: 2004-10-14T10:13:09+02:00
List-Id: <comp.lang.ada>

Georg Bauhaus wrote:

> Wojtek Narczynski <wojtek@power.com.pl> wrote:
> : Hello,
> : 
> : You can declare a record that will have zero bits size. Is this what you
> : want?
> : 
> :   type Frame_Mark is null record;
> 
> And maybe add a rep clause,
> 
>    type Nothing_At_All is null record;
>    for Nothing_At_All'size use 0;

That's for the type. If you actually use the type:

X: Nothing_At_All;
Y : aliased Nothing_At_All;

then X'Size is could still be >0. And Y'Size must be >0  since Y need to
have an unshared address to be aliased.

Martin

-- 
mailto://krischik@users.sourceforge.net
http://www.ada.krischik.com