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,bfa00be8f7a5ae46
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!postnews.google.com!j8g2000cwa.googlegroups.com!not-for-mail
From: "Lance" <lanceboyle@qwest.net>
Newsgroups: comp.lang.ada
Subject: Re: Compare these two (sub)type declarations
Date: 4 Jul 2006 13:01:10 -0700
Organization: http://groups.google.com
Message-ID: <1152043270.449772.302270@j8g2000cwa.googlegroups.com>
References: <1152006378.935306.287820@m79g2000cwm.googlegroups.com>
   <1152008738.616133.149850@m79g2000cwm.googlegroups.com>
NNTP-Posting-Host: 63.229.83.84
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
X-Trace: posting.google.com 1152043276 28389 127.0.0.1 (4 Jul 2006 20:01:16
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Tue, 4 Jul 2006 20:01:16 +0000 (UTC)
User-Agent: G2/0.2
X-HTTP-UserAgent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X;
 en) AppleWebKit/418.8 (KHTML, like Gecko) Safari/419.3,gzip(gfe),gzip(gfe)
Complaints-To: groups-abuse@google.com
Injection-Info: j8g2000cwa.googlegroups.com; posting-host=63.229.83.84;
   posting-account=Ax24hA0AAABV39UFqUVhb0kauOuAbI3T
Xref: g2news2.google.com comp.lang.ada:5490
Date: 2006-07-04T13:01:10-07:00
List-Id: <comp.lang.ada>


Ludovic Brenta wrote:
> Lance writes :
> > What is the difference between these two declarations?
> >
> > subtype Foo is Integer;
>
> Foo is a subtype. It is compatible with Integer and with all other
> subtypes of Integer such as Natural and Positive, i.e. you can convert
> implicitly between all these subtypes. The compiler inserts range
> checks where appropriate.
>
> > and
> >
> > type Bar is new Integer;
> >
> > In fact, what _is_ the second declaration? Would variables of type Bar
> > not be allowed in expressions where Integers are expected?
>
> Bar is a derived type. It is not compatible with Integer, or with any
> subtype of Integer, so the compiler would reject a program that passes
> a Bar to a subprogram that expects an Integer. You can, however,
> convert _explicitly_ between Bar and Integer, just like between any two
> numeric types; the compiler inserts range checks as appropriate.
>
> HTH
>
> > Jerry
>
> Is it Lance, or Jerry now?
>

My name is Jerry B a u c k. I use the lanceboyle address for mailing
lists for spam control reasons (lance boil is a joke in English) and to
keep from polluting my "real namespace" on the internet. I always sign
as Jerry but surprisingly (to me), people usually reply to "Lance." I
live in Tempe, Arizona, USA where I am self-employed.

Thanks for your informative reply.
> -- 
> Ludovic Brenta.