220 24452 article Path: news.gmane.org!not-for-mail From: Matthew Woehlke Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: [tuple] extracting tuples out of a tuple Date: Wed, 17 Feb 2016 13:06:53 -0500 Lines: 39 Approved: news@gmane.org Message-ID: References: <7e08b6c5-853c-471e-b248-a9df7e8e27be@isocpp.org> <67c3c86d-3089-4f07-878a-3f3e706744df@isocpp.org> <42a29c5b-07e4-4e36-bab4-03a7e86ff905@isocpp.org> <6e02dbfe-01f3-4840-92ab-bcc8f7824348@isocpp.org> <586249ad-b4ae-4e40-bdf7-344a641ad4c9@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: ger.gmane.org 1455732433 20058 80.91.229.3 (17 Feb 2016 18:07:13 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 17 Feb 2016 18:07:13 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC37LBFWUIFBBR7NSK3AKGQELJ4T3EI@isocpp.org Wed Feb 17 19:07:06 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-lb0-f199.google.com ([209.85.217.199]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aW6VF-0007id-6j for gclcip-std-proposals@m.gmane.org; Wed, 17 Feb 2016 19:07:05 +0100 Original-Received: by mail-lb0-f199.google.com with SMTP id h8sf5580468lbh.3 for ; Wed, 17 Feb 2016 10:07:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=to:from:subject:date:lines:message-id:references:mime-version :content-type:user-agent:in-reply-to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=kIZW1vbMKmHarjsGQn/1PePhG8jz5XkJqfFzCS6BCZ4=; b=1wRk5K02qzH6r38cP7ThDrcTrqDc3wir7CbA+Y6CqthJxpuSs4rUkgu+hh7r4jX2Xj wBak+zK1g8EBGKPKUuBc9KzQcjYFbenMOMR1M7ktOS0CXdZhcYMXyQou21M6KhjTq5lQ 3rBI1xAQf/Ln648t2ome3WW96Ug9Mr6tDl76wPuah4dGTBLeZ/e/lbKOEBvV/9mJHl23 n+ATykZRN8G8FNMaigBc9bdJ3rbfIVZxFJa/0nB9KbSdifbbF6qbtfBI6LsZT5w2xnJR YN8M7N5ILabvuLH3Obo3kmpGjS1zaDVFAjWjk+vdL0Dzr/3/tAwYS3dkwYjDzhO7d5DK HBp X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:to:from:subject:date:lines:message-id:references :mime-version:content-type:user-agent:in-reply-to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=kIZW1vbMKmHarjsGQn/1PePhG8jz5XkJqfFzCS6BCZ4=; b=O2wUm9J2ZgA+msREV182x+tar7igfQXeg8fnz5D5dH0OBGqdOxnYnOOeePPJ1BkO2y jNuFg1Qhs2UQIvl4yVlL9DvPFoW/BXwY4eL/JiRNCWiDZO6EWu43iX1Mvf6c+bMfGM8b yMsCKmr32+7ynSXgHWQVa4czek2t+wt7g436CFuBJk2/EepmiWifsLs+ycWZHAvJH022 xFB3qqjNAJEEVmXLeplTrBs9Cdo6JnjSRpwH8V1mECoaLZ2s7hKMK1tO2E/RNHwudosx +q7NzAZHNpE2sa8uY6fNhIwLJCuQtB0mLDIE8ldIxkB8j4FbbTMenwlSl9g183sf8yAv X-Gm-Message-State: AG10YORoRorGwR0qtsE4+n0MkG/DilWw9uFsd+VZ3SUEIKaYNFUsEez1svfr24HHzdU4tA== X-Received: by 10.194.178.234 with SMTP id db10mr496503wjc.6.1455732424757; Wed, 17 Feb 2016 10:07:04 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.25.26.206 with SMTP id a197ls957432lfa.83.gmail; Wed, 17 Feb 2016 10:07:03 -0800 (PST) X-Received: by 10.25.0.6 with SMTP id 6mr1217556lfa.132.1455732423236; Wed, 17 Feb 2016 10:07:03 -0800 (PST) Original-Received: from plane.gmane.org (plane.gmane.org. [80.91.229.3]) by mx.google.com with ESMTPS id cm2si1541352lbb.127.2016.02.17.10.07.03 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 17 Feb 2016 10:07:03 -0800 (PST) Received-SPF: pass (google.com: domain of gclcip-std-proposals@m.gmane.org designates 80.91.229.3 as permitted sender) client-ip=80.91.229.3; Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1aW6VB-0007g8-9C for std-proposals@isocpp.org; Wed, 17 Feb 2016 19:07:01 +0100 Original-Received: from tripoint.kitware.com ([66.194.253.20]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 17 Feb 2016 19:07:01 +0100 Original-Received: from mwoehlke.floss by tripoint.kitware.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 17 Feb 2016 19:07:01 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 30 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: tripoint.kitware.com User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 In-Reply-To: X-Original-Sender: mwoehlke.floss@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of gclcip-std-proposals@m.gmane.org designates 80.91.229.3 as permitted sender) smtp.mailfrom=gclcip-std-proposals@m.gmane.org; dmarc=fail (p=NONE dis=NONE) header.from=gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org 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:24452 Archived-At: On 2016-02-17 04:40, Sam Kellett wrote: > my personal opinion is that hana's is much much much more obvious > (the lambda version of the example specifically), in no short reason > because it's interface is based on the existing standard library. why > do we need two syntax's in one language when we can do it all with > one? ....because parameter packs "don't exist" in a sense. Accordingly, it is *necessary* that there exists a language syntax to instruct the compiler how to turn them into real code. As I stated elsewhere, a lot of the ranting and railing I see here is directed not at unpacking, but at *fold expressions*. That's borderline off topic, and I'm not necessarily opposed to improving fold expressions. (Though I also agree with Nicol that fold expressions are at least as understandable, and in some cases more so, than hana.) The point about familiarity here is apt. The hana syntax is obtuse to anyone not familiar with it. Fold expressions... do have their own problems, but IMHO are easier to grasp for someone who is a total novice with both. > also yours appears to be inherently ungoogle-able. assuming i don't > understand either syntax, for louis' i type into google 'c++ hana::unpack', > what do i type to find the reference pages for yours? https://www.google.com/search?q=c%2B%2B+fold+expressions -- Matthew -- --- 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. Visit this group at https://groups.google.com/a/isocpp.org/group/std-proposals/. .