From 857573192985295698 X-Google-Thread: f78e5,516d54c6ff652958 X-Google-Attributes: gidf78e5,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newsfeed00.sul.t-online.de!newsfeed01.sul.t-online.de!t-online.de!newsfeed.vmunix.org!peer-uk.news.demon.net!kibo.news.demon.net!mutlu.news.demon.net!news.demon.co.uk!demon!stump.algebra.com!devnull From: dave@boost-consulting.com (David Abrahams) Newsgroups: comp.std.c++ Subject: Re: "moveable data type" in comparison with "r-value reference" Date: Thu, 12 Apr 2007 04:56:39 GMT Lines: 42 Sender: mail2news@demon.net Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: <87k5wi5kby.fsf@grogan.peloton> References: NNTP-Posting-Host: news.news.demon.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: news.demon.co.uk 1176353805 23626 158.152.254.254 (12 Apr 2007 04:56:45 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Thu, 12 Apr 2007 04:56:45 +0000 (UTC) X-Original-To: std-c++@mailman.ucar.edu X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/23.0.0 (gnu/linux) X-DMCA-Complaints-To: abuse@rcn.net X-Virus-Scanned: amavisd-new at csse.unimelb.edu.au X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Cancel-Lock: sha1:aTnlAqamQqjaaINLqeQnCgkeuvs= X-Received: (from fjh@localhost) by mulga.csse.unimelb.edu.au (8.13.8+Sun/8.13.8/Submit) id l3C4udfg007769; Thu, 12 Apr 2007 14:56:39 +1000 (EST) X-Path: comp-std-cpp-robomod!not-for-mail X-NNTP-Posting-Date: Wed, 11 Apr 2007 22:43:13 -0500 X-Delivered-To: std-c++@mailman.ucar.edu X-Postfilter: 1.3.34 X-Authentication-Warning: serv4.gc.dca.giganews.com: news set sender to poster@giganews.com using -f X-Newsgroups: comp.std.c++ Xref: g2news1.google.com comp.std.c++:8434 on Wed Apr 11 2007, Richard Smith wrote: > Grizlyk wrote: > >> I will try to continue to show differences between "moveable data type" and >> "r-value reference", in order to project, that even simplest kind of >> algorithms with moveable data type could not be implemented with the help of >> "r-value reference". > > I dispute this. Let me demonstrate. > > Let's invent a trivially simple algorithm that might gain from a > movable data type It's good of you to go to the trouble, but Howard has already implemented an entire standard library using rvalue references wherever possible, and done the timing tests to show that it produces dramatic improvements over the existing one when used with types that are move-enabled. So there's an existence proof that even nontrivial and complex algorithms can be implemented using rvalue references such that they're efficient with moveable data types. And one point you make in your post, but which I think Grizlyk keeps missing: using rvalue references one can write the algorithms *once* such that they work as efficiently as possible for both moveable and non-moveable data types. It isn't necessary for algorithms to distinguish moveable types from non-moveable data types. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com Don't Miss BoostCon 2007! ==> http://www.boostcon.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.comeaucomputing.com/csc/faq.html ]