From -1226258389857173703 X-Google-Thread: f78e5,d50382f3e5ec6b4e X-Google-Thread: 109fba,d50382f3e5ec6b4e X-Google-Attributes: gidf78e5,gid109fba,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news4.google.com!news.glorb.com!news2.euro.net!216.196.110.149.MISMATCH!border2.nntp.ams.giganews.com!border1.nntp.ams.giganews.com!nntp.giganews.com!pe2.news.blueyonder.co.uk!blueyonder!peer-uk.news.demon.net!kibo.news.demon.net!news.demon.co.uk!demon!stump.algebra.com!devnull From: jdennett@acm.org (James Dennett) Newsgroups: comp.std.c++,comp.lang.c++ Subject: Re: The issue of const maps and operator[] Date: Fri, 3 Dec 2004 16:19:55 GMT Organization: Cox Communications Lines: 43 Sender: mail2news@demon.net Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: References: <3171vsF37jfq7U1@individual.net> <41aef8cf$0$66398$14726298@news.sunsite.dk> NNTP-Posting-Host: news.news.demon.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.demon.co.uk 1102090840 1402 158.152.254.254 (3 Dec 2004 16:20:40 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Fri, 3 Dec 2004 16:20:40 +0000 (UTC) X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7) Gecko/20040616 X-Accept-Language: en-us, en X-Virus-Scanned: by amavisd-new at cs.mu.OZ.AU X-Path: comp-std-cpp-robomod!not-for-mail X-Received: (from fjh@localhost) by mulga.cs.mu.OZ.AU (8.12.10+Sun/8.12.9/Submit) id iB3GJuab009982; Sat, 4 Dec 2004 03:19:56 +1100 (EST) X-NNTP-Posting-Date: Fri, 03 Dec 2004 00:14:54 EST X-Delivered-To: std-c++@ucar.edu X-Spamscanner: mailbox4.ucsd.edu (v1.5 Aug 25 2004 09:28:35, 0.0/5.0 3.0.0) X-Authentication-Warning: fed1read07.mgt.cox.net: news set sender to newsmaster@cox.net using -f X-Newsgroups: comp.std.c++,comp.lang.c++ X-MailScanner: PASSED (v1.2.8 22083 iB35F17m033708 mailbox4.ucsd.edu) Xref: g2news1.google.com comp.std.c++:3564 comp.lang.c++:32577 Thorsten Ottosen wrote: > "James Dennett" wrote in message > news:YWxrd.191852$hj.44035@fed1read07... > > >>In spite of having found several discussions on this topic, I could not >>find mention of whether this issue is going to be addressed when C++ >>gets its next major revision. > > > |I find it enormously unlikely that this would be changed in the > |next revision of C++. > > yes true. but we are already looking into adding > > T& map::at( const Key& ); > const T& map::at( const Key& ) const; This is reasonable and somewhat consistent with the at member in other standard library class templates. > which should throw if nothing is found. > Alternatively, I guess we could use operator()(). I wouldn't like that: mymap[1] = 3; and mymap(1) = 3; would then both be valid, with different semantics in the case mymap.find(1) == mymap.end(); and identical semantics otherwise, but they look too similar. Let's be consistent, and use "at" when we mean range-checked access which throws if an element is absent. -- James --- [ 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 ]