From 358087847109758101 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,4441c5f6d7843223 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2002-09-04 16:37:55 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!kibo.news.demon.net!mutlu.news.demon.net!demon!mail2news.demon.co.uk!devnull From: sa_schreuder@wanadoo.nl (Sjoerd Schreuder) Newsgroups: comp.std.c++ Subject: Re: C++0x Wish List (explicit class) Date: Wed, 4 Sep 2002 23:37:54 +0000 (UTC) Organization: Euronet Internet Lines: 40 Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: <3D768036.3B2B9386@wanadoo.nl> References: <3D48C729.40503@spamnot.codeweavers.com> <8c8b368d.0208060921.43e9e9d5@posting.google.com> <3D589892.3050008@spamnot.codeweavers.com> <8c8b368d.0208150528.2bc34601@posting.google.com> <8c8b368d.0208220503.1c974370@posting.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: mail2news.demon.co.uk 1031182675 15489 10.0.0.1 (4 Sep 2002 23:37:55 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Wed, 4 Sep 2002 23:37:55 +0000 (UTC) X-Received: from mulga.cs.mu.oz.au ([128.250.1.22]) by news.demon.co.uk with esmtp (Exim 4.05) id 17mjib-00041g-00 for mail2news@news.news.demon.net; Wed, 04 Sep 2002 23:37:53 +0000 X-Received: from localhost (localhost [[UNIX: localhost]]) by mulga.cs.mu.OZ.AU id JAA23378; Thu, 5 Sep 2002 09:37:45 +1000 (EST) X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Path: comp-std-cpp-robomod!not-for-mail X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-Delivered-To: std-c++@ncar.ucar.edu X-Accept-Language: en X-Newsgroups: comp.std.c++ X-NNTP-Posting-Date: Wed, 04 Sep 2002 23:48:06 MEST Xref: archiver1.google.com comp.std.c++:13614 Adam Peterson wrote: > If I could mark a class explicit to suppress conversion > operators I don't specify, but somehow still get the compiler > ctor/asmts, I'd use explicit on every class. I get tired writing the 'standard' implementations for member functions all the time. swap(), strong exception safe operator=(), operator+() in terms of operator+=(). It's all in the books and could (should) be generated automatically. So here is my draft of a draft of a proposal. Let's reuse the keyword 'default'! After a member declaration, 'default' forces a compiler to generate the standard definition. This doesn't break any code, as default is already a keyword and it will be introduced at a place in the grammar it is not allowed at this moment. As soon as 'standard' implementations for certain functions are established, they could be added to the list of default-able functions. explicit class Foo { private: int a; public: Foo() : a(42) {} // do not want the default here Foo(const Foo &) default; const Foo &operator = (const Foo &) default; void swap(Foo &) default; // I wish.... }; Sjoerd Schreuder --- [ 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 ]