From -7911035634525957247 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,ccb40040597f37a7 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2003-03-10 06:32:57 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: dsp@bdal.de (Daniel Spangenberg) Newsgroups: comp.std.c++ Subject: Re: Extending enums (was Re: Forward declaration of enum) Date: Mon, 10 Mar 2003 14:32:52 +0000 (UTC) Lines: 47 Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: <3E6C739E.9850D2A5@bdal.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: mail2news.demon.co.uk 1047306772 19975 10.0.0.1 (10 Mar 2003 14:32:52 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Mon, 10 Mar 2003 14:32:52 +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 18sOKf-0005C1-00 for mail2news@news.news.demon.net; Mon, 10 Mar 2003 14:32:51 +0000 X-Received: from localhost (localhost [[UNIX: localhost]]) by mulga.cs.mu.OZ.AU id BAA09485; Tue, 11 Mar 2003 01:32:20 +1100 (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: de X-Newsgroups: comp.std.c++ X-Spam-Status: No, hits=-5.0 required=5.0 tests=QUOTED_EMAIL_TEXT,REFERENCES,SPAM_PHRASE_00_01, USER_AGENT_MOZILLA_XM,X_ACCEPT_LANG version=2.41 Xref: archiver1.google.com comp.std.c++:18244 Dave Harris schrieb: > It's not really a cast; more of a name resolution. I think it is a shame > enums do not have associated namespaces, so that we could write: > > enum Color { Red, Orange, Yellow }; > enum Fruit { Orange, Apple, Grapes }; > > Colour c = Colour::Orange; > > Currently the second line is ambiguous even if Orange is not used > subsequently, and the Colour::Orange syntax is not permitted. As a > workaround I usually put my own namespace, like: > > namespace Color { enum Type { Red, Orange, Yellow }; } > namespace Fruit { enum Type { Orange, Apple, Grapes } }; > > Colour::Type c = Colour::Orange; > > which works, but it is clumsy (eg there is no good name for the thing I > have called "Type"). > For the same reason, I nearly always encapsulate enumeration definitions into classes, like struct Color { enum Type { Red, Orange, Yellow }; }; because I like the stronger enforcement of the complete name resolution of class namespaces. Why do you think, that Color::Type" is not a convenient identifier? Actually I use the same identifier and I think it is both short and self-explaining. Greetings from Bremen/Germany Daniel Spangenberg --- [ 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 ]