220 23848 article Path: news.gmane.org!not-for-mail From: Matthew Woehlke Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: RFC: Unpacking tuples to value sequences Date: Tue, 19 Jan 2016 11:02:05 -0500 Lines: 69 Approved: news@gmane.org Message-ID: References: <1e75441d-d6c0-48d5-a122-3dbf504a061f@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 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1453219343 28495 80.91.229.3 (19 Jan 2016 16:02:23 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 19 Jan 2016 16:02:23 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC37LBFWUIFBBBN47G2AKGQELBZ4TTQ@isocpp.org Tue Jan 19 17:02:15 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wm0-f71.google.com ([74.125.82.71]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aLYjX-0004dD-G1 for gclcip-std-proposals@m.gmane.org; Tue, 19 Jan 2016 17:02:15 +0100 Original-Received: by mail-wm0-f71.google.com with SMTP id u188sf41475462wmu.3 for ; Tue, 19 Jan 2016 08:02:15 -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:content-transfer-encoding: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=sEWJpdRYUO1sCP/mYIoolhgw3NZshgPr+XjWkBUy0kI=; b=GbK50mwjfG6r4/N/OqwvUOQrpJvSqnDFnfJ6/ezV12xyceY/6Y6ibbR4bivFpkUEaB pcr9oAo0SJNbXNpCNQubEXuO8n4IBNjNPBYwvwb5aeM7hmbGGDy9Tqfe8sIxmVDueVEn sacrk7bCCVVqp0m6/+AxfrF9VhbXK3IQJha93BDg7N1+30t93Auh1dU7pbfm96lB/w4n /mcH93lw3XULjiXwog/XB1CY2ulTWrHbKRlTKgRMFkbUEANSzzexwEL76YW+23HikXHu YNNkiVJOrv9SNxcQ60DhOUtvn4SwLzUUQthTWVcJukJLctAeftPzk5a 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:content-transfer-encoding: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=sEWJpdRYUO1sCP/mYIoolhgw3NZshgPr+XjWkBUy0kI=; b=RlT2H4UORo3y0yOixbJmTmI9cgLm8glRmQnGIcoctUNRZSidk6uPrtYwgg1lErV4il XKyZmIO7sQetqgmKQjtyEEOkipSPU6NRh8bzRYQkFXPD1Hg/5882RBzuaSr6vicCqbuX hWSsgrUA7U6gtmY90vArGPrAim0SD+25Cp8uu5Q4CweY3INvWudCpCXhv3J6p9FAhA0M uvp/S2QTQ3agvL4UnLqsN1kr2wMt9PN2O1mSnkLWTQWVs0jjNohszPQ+0E2h3ns/klZw XchcZCjoet+U5h40cVAppH1LIDlIK6vELnC7qJU1C28pP5hcMUj X-Gm-Message-State: ALoCoQk/oM1Je7ZB5+IWzoy4wcN+FtolAP02NfNMMGdfLZ4QkDWjAS48GPsKU77iiAE9/TZoWbaK+7SHYcEm/K1EnxXM6IEFGA== X-Received: by 10.112.54.202 with SMTP id l10mr4060148lbp.14.1453219334813; Tue, 19 Jan 2016 08:02:14 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.25.163.10 with SMTP id m10ls628969lfe.73.gmail; Tue, 19 Jan 2016 08:02:13 -0800 (PST) X-Received: by 10.25.22.232 with SMTP id 101mr8937287lfw.44.1453219333213; Tue, 19 Jan 2016 08:02:13 -0800 (PST) Original-Received: from plane.gmane.org (plane.gmane.org. [80.91.229.3]) by mx.google.com with ESMTPS id t4si15057715lbr.207.2016.01.19.08.02.13 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 19 Jan 2016 08:02:13 -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 1aLYjT-0004aL-V8 for std-proposals@isocpp.org; Tue, 19 Jan 2016 17:02:12 +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 ; Tue, 19 Jan 2016 17:02:11 +0100 Original-Received: from mwoehlke.floss by tripoint.kitware.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 19 Jan 2016 17:02:11 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 51 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: <1e75441d-d6c0-48d5-a122-3dbf504a061f@isocpp.org> 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:23848 Archived-At: On 2016-01-19 10:29, Nicol Bolas wrote: > On Tuesday, January 19, 2016 at 10:21:25 AM UTC-5, Matthew Woehlke wrote: >> On 2016-01-19 01:41, Jens =C3=85kerblom wrote:=20 >>> Seems similar to my idea regarding structure bindings.=20 >> >> No, really it isn't. Structured binding and value sequence unpacking are= =20 >> related, but significantly different. I tried to make that clear in the= =20 >> beginning of the Rationale.=20 >> >> What can I say to make this clearer?=20 >=20 > He's talking about something he suggested earlier=20 > ,=20 > which he *calls* a form of "structured binding", but it's really somethin= g=20 > else. It's the ability to convert a tuple into a named parameter pack, vi= a=20 > a syntax that *looks* somewhat like structured binding. Yes, I found the thread again, and have some recollection of it :-). I can understand the argument that it "isn't structured binding, per se". Unless I am really confused, however, it's still *a* form of binding, which is (mostly) orthogonal to my proposal, besides that they both deal with (different aspects of) very similar concepts. On further consideration, however, I can see where my proposal might make the one referenced mostly irrelevant. IOW, if this: auto {x, y, z...} =3D some_tuple; ....translated to: auto x =3D get<0>(some_tuple); auto y =3D get<1>(some_tuple); auto z =3D make_tuple([2:]some_tuple); ....then Jens' proposal becomes much simplified and doesn't need to involve mucking about with parameter packs. But it would depend on mine in order to be able to use the "trailing bits" in the same ways that were proposed in that thread. (Please ignore various errors and gratuitous use of novel syntax in the above; it is just for illustrative purposes.) > You made some posts in that thread a month back, so you should be aware o= f=20 > it. My comments seem to have drifted from the "variadic" part and relate to "what is tuple-like?". (And... I mentioned this idea there, also :-).) --=20 Matthew --=20 ---=20 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 e= mail 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-propos= als/. .