From 4674125883644858282 X-Google-Thread: f78e5,6f042a6ff823c6a0 X-Google-Attributes: gidf78e5,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news2.google.com!proxad.net!news.cs.univ-paris8.fr!news.zanker.org!news.clara.net!wagner.news.clara.net!194.159.246.34.MISMATCH!peer-uk.news.demon.net!kibo.news.demon.net!news.demon.co.uk!demon!stump.algebra.com!devnull From: nagle@animats.com (John Nagle) Newsgroups: comp.std.c++ Subject: Re: Relation of enermy(anti-friend) Date: Fri, 27 Aug 2004 02:40:26 GMT Organization: SBC http://yahoo.sbc.com Lines: 36 Sender: mail2news@demon.net Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: <5QrXc.11946$OX3.7394@newssvr27.news.prodigy.com> References: NNTP-Posting-Host: news.news.demon.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.demon.co.uk 1093574430 23626 158.152.254.254 (27 Aug 2004 02:40:30 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Fri, 27 Aug 2004 02:40:30 +0000 (UTC) X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.6) Gecko/20040113 X-Spam-Checker-Version: SpamAssassin 2.64-mulga_r1 (2004-01-11) on mulga.cs.mu.OZ.AU X-Spam-Status: No, hits=-3.7 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=2.64-mulga_r1 X-Accept-Language: en-us, en, ja X-UserInfo1: SCSYQNONTRUARPLYZZODM^P@VZ\LPCXLLBWLOOAFEQR@ETUCCNSKQFCY@TXDX_WHSVB]ZEJLSNY\^J[CUVSA_QLFC^RQHUPH[P[NRWCCMLSNPOD_ESALHUK@TDFUZHBLJ\XGKL^NXA\EVHSP[D_C^B_^JCX^W]CHBAX]POG@SSAZQ\LE[DCNMUPG_VSC@VJM X-Path: comp-std-cpp-robomod!not-for-mail X-Received: (from fjh@localhost) by mulga.cs.mu.OZ.AU (8.12.10+Sun/8.12.9/Submit) id i7R2eQ19024369; Fri, 27 Aug 2004 12:40:26 +1000 (EST) X-NNTP-Posting-Date: Thu, 26 Aug 2004 16:35:13 EDT X-Spam-Level: X-Delivered-To: std-c++@ucar.edu X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Newsgroups: comp.std.c++ Xref: g2news1.google.com comp.std.c++:2224 Victor Bazarov wrote: > Kim, Seungtai wrote: > Have you encountered anything _in the real life_ that would be resolved > by introducing the "enemy" specifier? I haven't. There's a related situation where something similar might be relevant. C++ allows member functions of a class to access the private members of ANY objects of the class they can reach. This allows copy constructors, "swap", and similar functions. But it's unusual for a class to need to access private members of another object of the same class. There's no way to turn that access off, though. Perhaps there should be. The reason this matters is because it's a synchronization issue. If a class locks the "this" object on entrance to a public function member and unlocks it on exit, that protects the "this" object. It doesn't protect any other object the member function can access and mess with. If C++ were to address class-level synchronization, as Java does, this is an issue that should be addressed at that time. John Nagle Animats --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ]