220 27740 article Path: news.gmane.org!.POSTED!not-for-mail From: "D. B." Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Tuple syntax overhaul Date: Wed, 10 Aug 2016 08:01:52 +0100 Lines: 93 Approved: news@gmane.org Message-ID: References: <02ef4ab0-251d-4613-8f07-877855f9a86c@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=001a114b3dac65f8100539b239cb X-Trace: blaine.gmane.org 1470812519 7703 195.159.176.226 (10 Aug 2016 07:01:59 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 10 Aug 2016 07:01:59 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCWNZ4ECS4GBBYVCVO6QKGQEAJUOLKQ@isocpp.org Wed Aug 10 09:01:55 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wm0-f72.google.com ([74.125.82.72]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bXNWU-0001rY-M8 for gclcip-std-proposals@m.gmane.org; Wed, 10 Aug 2016 09:01:54 +0200 Original-Received: by mail-wm0-f72.google.com with SMTP id 1sf48551752wmz.2 for ; Wed, 10 Aug 2016 00:01:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject: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=0oTO9Aj2I1QfhhEy+/Nid7OAl9BB9IuNiTHVvkvQhjU=; b=YiRfLK4nsKGTtN6PDPbfA0OJKHeH78opLCazbmf+ety8b47/1Wm5Azqvbnsir4/Ozu YzhHQwQeAuEy3Wvz5KykrH5iXSWwyvMavWpwFKYYbpRmoP8bQYamZrWo5QW68Z/ewjtU N9Uq6CaJFV2p4bS/82mIsjtMN1h0hJmSse7VC0g94ZjOcl4IYPPfvZaSmEfcstS1yGa2 yZpGVPs2ckifuZ3ikoNGjIisAaDD/f1qNJuQ6/AE97bs6qJuqH4qJB87CxUmWnABejzK z5qEbwGjrzEp65Iioei6DxdR4M7liQLh41LOJHb+JVp6PeqeoDYUQk1caB48g4wSwSNX DopQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject: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=0oTO9Aj2I1QfhhEy+/Nid7OAl9BB9IuNiTHVvkvQhjU=; b=S/j/XQrng28gpIDIM9LCuK7DzP8PsvAHd92exxYCmA11WbErI8rRzl0S4nwyDkvab9 RnKvErRqeq2LsAWZ+yE2pwx3pV1kHdiEVhfZEzg/x+3W+t0WeAXZchw1VsewrrdMlxHT 9/ai5u4sN+s63guN4XnsOQIUFRloLonb/fWlBQR2G9LFcDf7naGdEB3fHd79A725LAJL hcXduEFbwYk+P/9p0G+JS/m/w/Q94HcA8GXF4zQcQjpDWyMtTt+fAG7nl22CuFz0pLiY 9hAz33PDzB/DS/LEHB/5n1GMjp+PcdRS4Tt90Y3NqSMKOdTu2k4tOHZeflRVHS/0Qmd0 dyjg== X-Gm-Message-State: AEkoouulPe3Rao8OqO1zW6MPtjUoC8/vskG5cPODbZdauG0n5CeAi8x2xbZo7RFTxXC6EA== X-Received: by 10.28.196.67 with SMTP id u64mr186570wmf.3.1470812515112; Wed, 10 Aug 2016 00:01:55 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.28.137.4 with SMTP id l4ls3785152wmd.26.gmail; Wed, 10 Aug 2016 00:01:54 -0700 (PDT) X-Received: by 10.28.182.84 with SMTP id g81mr1451119wmf.20.1470812514045; Wed, 10 Aug 2016 00:01:54 -0700 (PDT) Original-Received: from mail-wm0-x235.google.com (mail-wm0-x235.google.com. [2a00:1450:400c:c09::235]) by mx.google.com with ESMTPS id 3si38406437wjs.264.2016.08.10.00.01.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Aug 2016 00:01:54 -0700 (PDT) Received-SPF: pass (google.com: domain of db0451@gmail.com designates 2a00:1450:400c:c09::235 as permitted sender) client-ip=2a00:1450:400c:c09::235; Original-Received: by mail-wm0-x235.google.com with SMTP id o80so82193489wme.1 for ; Wed, 10 Aug 2016 00:01:54 -0700 (PDT) X-Received: by 10.28.158.142 with SMTP id h136mr1570337wme.10.1470812513497; Wed, 10 Aug 2016 00:01:53 -0700 (PDT) Original-Received: by 10.28.15.15 with HTTP; Wed, 10 Aug 2016 00:01:52 -0700 (PDT) In-Reply-To: <02ef4ab0-251d-4613-8f07-877855f9a86c@isocpp.org> X-Original-Sender: db0451@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of db0451@gmail.com designates 2a00:1450:400c:c09::235 as permitted sender) smtp.mailfrom=db0451@gmail.com; dmarc=pass (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-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:27740 Archived-At: --001a114b3dac65f8100539b239cb Content-Type: text/plain; charset=UTF-8 But AFAICT the Committee try avoid adding core-langauage features that can be adequately served by library usage. Also, the tuple syntax is now heavily established and entrenched. How would one keep that version around while adding a new one, and ensure both were synced up? Rather, what would be best would be to make parts of tuples into language built-in syntax, which would then transform to particular calls to the existing stdlib class and/or pieces of more literal but more verbose syntax. Like std::initializer_list and range-for respectively. And doing it this way might mean the benefits could be extended to other types, not just tuples. Lastly, do you think your proposed grammar would be unambiguous enough to use? Lambdas exist, as do the following... On Wed, Aug 10, 2016 at 12:55 AM, HarD Gamer wrote: > THAT IS SOMETHING LIKE THIS IN C++17 sintax. check here isocpp.com DON'T SHOUT. And if you're going to refer people to something, at least provide a proper link or something you can use. You're probably talking about structured binding, but that does the opposite thing: given [a, b, c] = RHS, it unpacks some struct or tuple RHS into the individual variables specified on the left. Also, it seems that what I alluded to above about making certain bits of syntax language built-ins already applies here, since [structured, binding] knows what to do with a tuple on the RHS, despite that being a template class. -- 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/CACGiwhEhVkQJxNtxaDKG5v8fG7%2BY4K70nY7fSBAGUg4csK7Nbg%40mail.gmail.com. --001a114b3dac65f8100539b239cb Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
But AFAICT the Committee try av= oid adding core-langauage features that can be adequately served by library= usage. Also, the tuple syntax is now heavily established and entrenched. H= ow would one keep that version around while adding a new one, and ensure bo= th were synced up?

Rather, what wou= ld be best would be to make parts of tuples into language built-in syntax, = which would then transform to particular calls to the existing stdlib class= and/or pieces of more literal but more verbose syntax. Like std::initializ= er_list and range-for respectively. And doing it this way might mean the be= nefits could be extended to other types, not just tuples.

Lastly, do you think your proposed grammar would be = unambiguous enough to use? Lambdas exist, as do the following...
<= div class=3D"gmail_extra">
On Wed, Aug 10, 20= 16 at 12:55 AM, HarD Gamer <rodrigojose690@gmail.com>= wrote:
THAT IS SOMETHING LIKE THIS IN C++17 sintax. check here isocpp.com<= /blockquote>
DON'T SHOUT. And if you're going to refer people t= o something, at least provide a proper link or something you can use.
You're probably talking about structured binding, but that does the o= pposite thing: given [a, b, c] =3D RHS, it unpacks some struct or tuple RHS= into the individual variables specified on the left.

Als= o, it seems that what I alluded to above about making certain bits of synta= x language built-ins already applies here, since [structured, binding] know= s what to do with a tuple on the RHS, despite that being a template class.<= br>

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