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-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,8eff44ec1bcf8433 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-10-17 06:11:31 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.tele.dk!small.news.tele.dk!195.86.7.162!newsfeed.wirehub.nl!news-hub.cableinet.net!blueyonder!peer.news.eu-x.com!server2.netnews.ja.net!newshost.central.susx.ac.uk!news.bton.ac.uk!not-for-mail From: John English Newsgroups: comp.lang.ada Subject: Re: Container reqs Date: Wed, 17 Oct 2001 13:40:48 +0100 Organization: University of Brighton Message-ID: <3BCD7C50.647ADBD0@brighton.ac.uk> References: <9qctpn$lil$1@news.huji.ac.il> <3BCA86C7.BB252751@acm.org> <%jYy7.31350$ev2.37672@www.newsranger.com> NNTP-Posting-Host: pc2je.it.bton.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: saturn.bton.ac.uk 1003322763 19526 193.62.183.154 (17 Oct 2001 12:46:03 GMT) X-Complaints-To: news@bton.ac.uk NNTP-Posting-Date: 17 Oct 2001 12:46:03 GMT X-Mailer: Mozilla 4.7 [en-gb] (Win95; U) X-Accept-Language: en Xref: archiver1.google.com comp.lang.ada:14798 Date: 2001-10-17T12:46:03+00:00 List-Id: Ted Dennison wrote: > > In article <3BCA86C7.BB252751@acm.org>, Jeffrey Carter says... > > > >Ehud Lamm wrote: > >> * Memory handling is important, but we don't want to have to do > >> library-level instantaions beacuse of Controlled types. > > > >Disagree. For industrial-strength use the precision of memory control > >using controlled types outweighs the inconvenience of requiring > >library-level instantiations. > > I don't think this one is worth arguing, because its probabaly unattainable > anyway. The problem isn't controlled types per se. The problem is that you can't > derive from a type at a lower level than the parent is declared. If you > implement your components with tagged types, you will almost certinaly bump into > this limitation whether controlled types are used or not. Hmm, the STL doesn't use inheritance, it's all done with templates. Tagged types probably aren't needed at all (other than as derivations of controlled). And you can use tricks to get around the library-level problem, e.g. have a library-level parent package which defines a private controlled type and generic children which make use of those controlled objects as components in other composite types... Maybe the STL approach, with an optional "allocator" parameter, is the way to go for memory allocation issues? ----------------------------------------------------------------- John English | mailto:je@brighton.ac.uk Senior Lecturer | http://www.comp.it.bton.ac.uk/je Dept. of Computing | ** NON-PROFIT CD FOR CS STUDENTS ** University of Brighton | -- see http://burks.bton.ac.uk -----------------------------------------------------------------