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,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.101.76.1 with SMTP id u1mr75135pgq.79.1504724187349; Wed, 06 Sep 2017 11:56:27 -0700 (PDT) X-Received: by 10.36.51.147 with SMTP id k141mr49633itk.14.1504724187304; Wed, 06 Sep 2017 11:56:27 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!paganini.bofh.team!weretis.net!feeder6.news.weretis.net!feeder.usenetexpress.com!feeder-in1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!k189no481497itk.0!news-out.google.com!p6ni867itp.0!nntp.google.com!127no483649itw.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Wed, 6 Sep 2017 11:56:27 -0700 (PDT) In-Reply-To: <87a827akgj.fsf@jacob-sparre.dk> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=83.255.112.230; posting-account=NT38RwoAAAB4_OO_uw8yHtNaa9Hkjukk NNTP-Posting-Host: 83.255.112.230 References: <4dc188de-802b-41ad-9cdd-b8246eb9a1c7@googlegroups.com> <47cc6474-8b75-4644-92d0-bd1f694c20e7@googlegroups.com> <338b355a-dee4-4c73-b00e-09d9a8430fb1@googlegroups.com> <87a827akgj.fsf@jacob-sparre.dk> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <19e14b61-0d81-4a9e-a99f-d88a3a1a9070@googlegroups.com> Subject: Re: Community Input for the Maintenance and Revision of the Ada Programming Language From: =?UTF-8?B?Sm9oYW4gU8O2ZGVybGluZCDDhXN0csO2bQ==?= Injection-Date: Wed, 06 Sep 2017 18:56:27 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Xref: news.eternal-september.org comp.lang.ada:47952 Date: 2017-09-06T11:56:27-07:00 List-Id: On Wednesday, September 6, 2017 at 5:57:34 PM UTC+2, Jacob Sparre Andersen = wrote: > Johan S=C3=B6derlind =C3=85str=C3=B6m wrote: >=20 > > I do not think that accessing a element from a array is a complicated > > thing and starting from a zero indexed array is even simpler, then why > > would a compiler not guarantee such a simple thing to work? >=20 > One possibility is that constrained and unconstrained subtypes of the > same subtype may have slightly different memory layouts. >=20 > Or maybe the bounds of the array are stored at the beginning of the > memory structure (where else can we put them?), and your overlaying > changes the subtype of the (possibly constant) array passed to it, by > overwriting the bounds. >=20 > Randy has written a part of at least one Ada compiler, so he can > probably come up with some more concrete examples. >=20 > Greetings, >=20 > Jacob > --=20 > "Good enough for physics" -- Ridcully I did not thought of that. Now I have been trying to collide First and Last= but I can not seem to do it with GNAT, the variables always represent thei= r specified boundary even with shared memory. GNAT folks probably implement= ed something in case of me writing reckless code.