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,b0f4738b8e27cca3 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-11-25 12:12:30 PST Path: archiver1.google.com!news2.google.com!news.maxwell.syr.edu!sn-xit-03!sn-xit-04!sn-xit-01!sn-post-02!sn-post-01!supernews.com!corp.supernews.com!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: Problem with protected type Date: Tue, 25 Nov 2003 14:09:54 -0600 Organization: Posted via Supernews, http://www.supernews.com Message-ID: References: X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4910.0300 X-Complaints-To: abuse@supernews.com Xref: archiver1.google.com comp.lang.ada:2939 Date: 2003-11-25T14:09:54-06:00 List-Id: "Ludovic Brenta" wrote in message news:m38ym4xuqq.fsf@insalien.org... > > And can I create inheritable protected classes? > > No. This has been proposed as an extension to the language [1] back > in 2000, but the discussions concluded that there was no demand for > this feature from paying customers, so therefore no compiler vendors > were going to implement it. > > [1] http://www.ada-auth.org/cgi-bin/cvsweb.cgi/AIs/AI-00250.TXT?rev=HEAD That's not quite the right conclusion. Besides the importance question, there are also technical issues related to locking that are quite difficult to solve usefully. Moreover, having the code for locking an protected object in several units could be very difficult to understand and analyze. The ARG decided to look at protected interfaces instead (that is, provide interface inheritance, but not implementation inheritance.) That's AI-345. I don't know if these will be adopted (there are several issues that need to be resolved), but it looks like a more promising approach than that given in AI-250. Randy Brukardt.