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=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,fc7fc1b95198137d X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-10-30 06:42:36 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!fr.usenet-edu.net!usenet-edu.net!enst!enst.fr!not-for-mail From: "M. A. Alves" Newsgroups: comp.lang.ada Subject: Re: Ada Address = C pointer ? Date: Tue, 30 Oct 2001 14:41:33 +0000 (GMT) Organization: ENST, France Sender: comp.lang.ada-admin@ada.eu.org Message-ID: Reply-To: comp.lang.ada@ada.eu.org NNTP-Posting-Host: marvin.enst.fr Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Trace: avanie.enst.fr 1004452955 92930 137.194.161.2 (30 Oct 2001 14:42:35 GMT) X-Complaints-To: usenet@enst.fr NNTP-Posting-Date: Tue, 30 Oct 2001 14:42:35 +0000 (UTC) To: Return-Path: X-X-Sender: In-Reply-To: Errors-To: comp.lang.ada-admin@ada.eu.org X-BeenThere: comp.lang.ada@ada.eu.org X-Mailman-Version: 2.0.6 Precedence: bulk List-Help: List-Post: List-Subscribe: , List-Id: comp.lang.ada mail<->news gateway List-Unsubscribe: , List-Archive: Errors-To: comp.lang.ada-admin@ada.eu.org X-BeenThere: comp.lang.ada@ada.eu.org Xref: archiver1.google.com comp.lang.ada:15411 Date: 2001-10-30T14:41:33+00:00 On Tue, 30 Oct 2001, Matthew Heaney wrote: > "M. A. Alves" wrote in message > news:mailman.1004446456.21280.comp.lang.ada@ada.eu.org... > > However, I am still not sure of the equivalence between null (a value of > > Pointer) and NULL (C), i.e. is it garanteed that if the C function returns > > NULL get_long_array returns null? > > Yes. See RM95 B3.2 (17). Yes, I know that null = NULL seems an obvious interpretation of "C-compatible", but the RM is not known for relying on the obvious. So, either way (Interfaces.C.Pointers vs. System.Address_To_Access_Conversions), _assumptions_ are made (by the programmer). But I agree a Pointers idiom is a viable, perhaps better, alternative to a System one. Perhaps I'll change my code some day. -- , M A R I O data miner, LIACC, room 221 tel 351+226078830, ext 121 A M A D O Rua Campo Alegre, 823 fax 351+226003654 A L V E S P-4150 PORTO, Portugal mob 351+939354002