From 1506175006905381007 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,ccbfcafab96cf493 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2001-12-07 17:03:04 PST Path: archiver1.google.com!news1.google.com!sn-xit-02!supernews.com!news.tele.dk!small.news.tele.dk!194.42.224.136!diablo.netcom.net.uk!netcom.net.uk!dispose.news.demon.net!news.demon.co.uk!demon!mail2news.demon.co.uk!not-for-mail From: "James Kuyper Jr." Newsgroups: comp.std.c++ Subject: Re: Proposol to increase robustness of programs Date: Sat, 8 Dec 2001 01:02:20 GMT Organization: Posted via Supernews, http://www.supernews.com Approved: Fergus Henderson , moderator of comp.std.c++ Message-ID: <3C116753.1ABD9C5A@wizard.net> References: <3BFE97B3.91430FB1@wanadoo.fr> <3C058126.36357A00@acm.org> <3C06A0CE.E91638E8@acm.org> <3C0C1E25.1A0247AD@acm.org> <3C0D410B.7198B21D@wanadoo.fr> <3C0D4878.A86E882E@acm.org> <7dc3b1ea.0112060840.69c166cc@posting.google.com> <3C0FD9D7.8F1845C4@acm.org> <3C102097.B3C1FEA8@wizard.net> <3C10CE1E.E556E183@acm.org> X-Trace: mail2news.demon.co.uk 1007773345 mail2news:9680 mail2news mail2news.demon.co.uk X-Complaints-To: abuse@demon.net X-Mail2News-Path: news.demon.net!mulga.cs.mu.oz.au X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-Accept-Language: en MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 71 Xref: archiver1.google.com comp.std.c++:8559 Pete Becker wrote: > > "James Kuyper Jr." wrote: > > > > Pete Becker wrote: > > > > > > Peter Dimov wrote: > > > > > > > > After changing a base virtual function signature, the typical > > > > procedure is to locate all overriders - by hand - and fix them. Rarely > > > > does a programmer wait for the tests to fail. They will. No new > > > > information would be gained. > > > > > > > > With consistent use of 'override', the process is automated. > > > > > > > > > > No, it turns into compile-and-see-what-breaks, which is rarely a good > > > approach to software engineering. > > > > I'm sorry, but I have to disagree. Compile-and-see-what-breaks is one of > > the many important tools that belongs in every programmer's tool chest. > > No. When programmers resort to this it's because they're tired of > thinking. I think all day long. It's what I get paid for. Getting tired of thinking is a normal everyday event. No - make that "hourly", not "everyday". I prefer to let the compiler spend it's exceedingly cheap time thinking about the things that it's much better equipped to think about than I am. I prefer to concentrate my own limited and expensive supply of time thinking about issues that I'm much better equipped to handle than the compiler is. > > I think you're missing out on one of the most basic problems 'override' > > helps with: spelling errors. Without 'override', a misspelled overrider > > is a perfectly legal definition of a completely different member > > function. If you are consistently misreading it as having been correctly > > spelled (a mistake that's easy for human beings to make), it can be very > > difficult to detect the problem through testing, or debugging. > > Huh? If you haven't overridden a base-class virtual function, then your > test code that exercises the derived-class overrider will fail. That's > not at all hard: it just works. All that unit test will tell me is that there's a problem. If I don't notice the misspelling, that test WON'T tell me where the problem is. This is perfectly normal, at least for those of us capable of making spelling errors. If a person commits a particular misspelling, that person is also likely to not notice that misspelling when reading it. With an 'override' keyword, any decent compiler would give me a message that points me far more precisely at the actual source of the problem. It will do so as soon as I compile the code, without even waiting for the unit test. > > Compilers, on the other hand, excel at detecting that kind of error. > > Maybe you spell perfectly, but I don't, and neither do most of the other > > programmers I've ever worked with. > > There are lots of places where this could happen. Changing the language > to attack one that's easy to test for isn't particularly useful. Nor is it useless. As as judgment call, I think it's usefulness is large enough to justify the change, but I don't expect agreement on judgment calls. --- [ 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.research.att.com/~austern/csc/faq.html ]