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,e568be4d901b052d,start
X-Google-NewGroupId: yes
X-Google-Attributes: gida07f3367d7,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
X-Received: by 10.181.13.205 with SMTP id fa13mr9143225wid.3.1356708168023;
        Fri, 28 Dec 2012 07:22:48 -0800 (PST)
Path: 
 i11ni320508wiw.0!nntp.google.com!proxad.net!feeder1-2.proxad.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!mx04.eternal-september.org!.POSTED!not-for-mail
From: =?UTF-8?B?w4FsZXggUi4=?=  Mosteo <alejandro@mosteo.com>
Newsgroups: comp.lang.ada
Subject: Dimensions in Ada
Date: Fri, 28 Dec 2012 16:22:43 +0100
Organization: A noiseless patient Spider
Message-ID: <kbkdg7$c5u$1@dont-email.me>
Mime-Version: 1.0
Injection-Date: Fri, 28 Dec 2012 15:22:47 +0000 (UTC)
Injection-Info: mx04.eternal-september.org;
 posting-host="ecb640279bc7d37568b22d1f3cb7cdd8";
	logging-data="12478"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX1+FdWyY9mOvEcg/0q8f99NF"
User-Agent: KNode/4.9.4
Cancel-Lock: sha1:6ymHaIRroVJl7Anz1JbiZ//0v0E=
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7Bit
Date: 2012-12-28T16:22:43+01:00
List-Id: <comp.lang.ada>

I have vague remembrances of past discussions about unit systems in Ada; at 
least three ways of doing it, none of them totally satisfying.

Today I have stumbled in the following Ada Gem from AdaCore:

"This Gem outlines the new GNAT dimensionality checking system. This feature 
relies on Ada 2012 aspect specifications, and is available from version 
7.0.1 of GNAT onwards."

http://libre.adacore.com/adaanswers/gems_single/gem-136-how-tall-is-a-
kilogram

I lack the knowledge to judge it against the other options, which I don't 
even remember, but I'd like to hear opinions from interested parties. It 
uses a GNAT-specific aspect, so may be that provides (or not) the necessary 
magic to close the gap in previous approaches? That's what first comes to my 
mind...