From 3263215714148263041 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,6a0e273cd04a6fa1 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2002-01-15 07:45:01 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!dispose.news.demon.net!news.demon.co.uk!demon!mail2news.demon.co.uk!not-for-mail From: Pete Becker Newsgroups: comp.std.c++ Subject: Re: new meaning of explicit keyword Date: Tue, 15 Jan 2002 15:44:54 GMT Organization: Dinkumware, Ltd Approved: Fergus Henderson , moderator of comp.std.c++ Message-ID: <3C443846.C1742C70@acm.org> References: <92ce342f.0201100428.49e3dd92@posting.google.com> <3C3DE3E6.F27385B2@acm.org> <3C3E11E4.E454ABB0@acm.org> <92ce342f.0201110304.3045ea38@posting.google.com> <3C3F961A.AFDD9708@acm.org> X-Trace: mail2news.demon.co.uk 1011109498 mail2news:13622 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) Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit NNTP-Posting-Date: 15 Jan 2002 14:09:30 GMT X-Accept-Language: en Lines: 43 Xref: archiver1.google.com comp.std.c++:9057 Francis Glassborow wrote: > > In article <3C3F961A.AFDD9708@acm.org>, Pete Becker > writes > >A couple of people have mentioned templates as a reason for having > >explicit conversion operators, but so far I haven't seen anyone explain > >what this means. How do templates benefit from someone being able to say > >"if you want this conversion you must write a cast"? > > I think you have it the wrong way round. That is, you think that the part of my message that you snipped, which contains the argument that you are objecting to, has it the wrong way round. I didn't make that argument, I replied to it. Regardless, newsgroup discussions should be about the logic of the argument, not about the person who presented it. > There are times where we need > conversion (via conversion operators) for templates. Conversion > functions do not cut it because there is no uniform naming convention > for them. OTOH I do not want to allow the compiler to use my conversion > operator elsewhere for all the many reasons that we know that conversion > operators are often poor design. > There is no uniform naming convention for many things that we do inside templates. The solution is to specify requirements for the types that the template is instantiated on, such as having a conversion function with a particular name and calling convention. If class designers choose to require conversion operators, knowing that they provide the wrong semantics, then they've made a mistake. There is no need to change the language definition to "fix" this. -- Pete Becker Dinkumware, Ltd. (http://www.dinkumware.com) --- [ 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 ]