220 33547 <722a37ea-6d3c-952a-f75e-376259a427cb@otoy.com> article Path: news.gmane.org!.POSTED!not-for-mail From: Ross Smith Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: A more advanced switch Date: Thu, 3 Aug 2017 09:18:33 +1200 Lines: 42 Approved: news@gmane.org Message-ID: <722a37ea-6d3c-952a-f75e-376259a427cb@otoy.com> References: <9d888362-46f2-4317-b4ea-4376159d8ef1@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed X-Trace: blaine.gmane.org 1501708724 4225 195.159.176.226 (2 Aug 2017 21:18:44 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 2 Aug 2017 21:18:44 +0000 (UTC) User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCQ4ZXOXM4IK5A4JZQCRUBHV4TTCU@isocpp.org Wed Aug 02 23:18:39 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qk0-f197.google.com ([209.85.220.197]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dd12I-0000TN-2F for gclcip-std-proposals@m.gmane.org; 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[2607:f8b0:400e:c05::22e]) by mx.google.com with ESMTPS id x11si10089797pfe.328.2017.08.02.14.18.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Aug 2017 14:18:38 -0700 (PDT) Received-SPF: pass (google.com: domain of ross.smith@otoy.com designates 2607:f8b0:400e:c05::22e as permitted sender) client-ip=2607:f8b0:400e:c05::22e; Original-Received: by mail-pg0-x22e.google.com with SMTP id u185so25871583pgb.1 for ; Wed, 02 Aug 2017 14:18:38 -0700 (PDT) X-Received: by 10.99.43.212 with SMTP id r203mr24111037pgr.321.1501708717658; Wed, 02 Aug 2017 14:18:37 -0700 (PDT) Original-Received: from [10.0.0.87] (125-236-198-58.adsl.xtra.co.nz. [125.236.198.58]) by smtp.gmail.com with ESMTPSA id t29sm14025843pfl.4.2017.08.02.14.18.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Aug 2017 14:18:36 -0700 (PDT) Original-Newsgroups: gmane.comp.lang.c++.isocpp.proposals In-Reply-To: Content-Language: en-US X-Original-Sender: ross.smith@otoy.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@otoy-com.20150623.gappssmtp.com header.b=RxtZQAIC; spf=pass (google.com: domain of ross.smith@otoy.com designates 2607:f8b0:400e:c05::22e as permitted sender) smtp.mailfrom=ross.smith@otoy.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:33547 Archived-At: On 2017-08-02 21:20, Bo Persson wrote: > On 2017-08-01 23:53, Vishal Oza wrote: >> I like the idea of adding new of adding to the switch statement but I >> think lets take it futher >> switch (v) >> { >> case v= [1,5]: //incusive 1 to 5 1 <= v <= 5 >> Dosomething(); >> break; >> case v = (5, 10): //exclusive range 5 < v < 10 >> doSomethingelse1(); >> break; >> case v = (10, 50 ]: // 10 < v <= 50 >> doSomethingElse2(); >> break; >> case v = (50,...) // 50 < v >> doSomethingElse3(); >> break; >> case v = 50: >> doSomethingElse4(); >> break; >> } >> Valid for only if v is numeric also add multi variable values and strings >> > > If you have large ranges, the compiler might translate that similar to > an if-statement anyway. Especially the (50,...) cannot easily be used in > a jump table. There's only so much elaboration that could be added to the switch statement before it stops offering any meaningful advantage in convenience or readability over just manually writing the equivalent sequence of if-elses. Ross Smith -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/722a37ea-6d3c-952a-f75e-376259a427cb%40otoy.com. .