220 24011 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: Mon, 25 Jan 2016 10:32:34 -0500 Lines: 42 Approved: news@gmane.org Message-ID: References: <6f3ece34-e302-4d95-afd0-4c1924e8a780@isocpp.org> <6ad65a24-8a2e-4053-b9c9-80d296d98e7d@isocpp.org> <72de7daf-93af-4e55-95ea-67898bd2a5f6@isocpp.org> <29e7b2a0-05fb-46e2-92bc-2a83f8a1e53c@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 1453735983 22674 80.91.229.3 (25 Jan 2016 15:33:03 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 25 Jan 2016 15:33:03 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC37LBFWUIFBBHUATG2QKGQEQWIUKOY@isocpp.org Mon Jan 25 16:32:49 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 1aNj8K-0000sE-Pn for gclcip-std-proposals@m.gmane.org; Mon, 25 Jan 2016 16:32:48 +0100 Original-Received: by mail-lb0-f199.google.com with SMTP id zr1sf45781196lbb.1 for ; Mon, 25 Jan 2016 07:32:48 -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=QNlrrBUMFq2HFCVmHtZUJIEFnV5LpqO32g5EFS66Jbc=; b=jfDtwI/U7S5umYKzsQ+59fAGEh2gj0LzNGVE8Np4VfktBqu9NI+FTYGahwiCMMDjJT SR/FiEJBxjYxMHBGDNZB1JtRqysg3Rk1xYxpjJ0yCOlPTvcCub/H4NfXVxyJOvLXv3/C o/nAVSRUbz06pCOa+6pSJnLEs5A2C8DB2lQ0HEVgr6NTydl8+O/jCeGGgLCle5GLBzSZ DXKgKOMi1HLIIXinZW3Mtl6wnk02qX3PnOmtNM3Dzg2M9eKlXSGpRVQhGlKg6zQKHV/u TcyTRouV6SbxjmiVNTEMcohImMjJQmZZGYIu+Kv9JyjM7d1T7fDZnsqRCuC8VSF8PXbe 9QB 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=QNlrrBUMFq2HFCVmHtZUJIEFnV5LpqO32g5EFS66Jbc=; b=BbuHFR78b1PbQ/qKgIvlJU3UDzg3+qHVifB0MI5n/KyGLC47C1TB75mHkPxtL1mJ/6 tagEMQ/OMUEwlDrbFkR/5Gj3Vx/ZUn9TnLLES10uTAAEFb2GYFuK/vWvJCn+mAHGUiZu zj3mRxKPVSXUJ4pn+vw+ixg3tILJhXKDDSkpFjuP+jGSRDmTz0KLIDesVb4t2HbNMem9 5Q2srYrDY6PXF8cW1sNQ3ez4QjHZaF1Awqv+0u27wFPLTG9lOXPxl7YBXXsjVj10wF1l V6o6GqLKndsYE3bYSb3ANa0VBCdcNI28qcm66/9FY3Cxpxn+sX558a5GgqWxYqBNoFj1 X-Gm-Message-State: AG10YOSH3ECma7MfczGzJrxkLc8fUZ8K+Ve+YTei62KZ0Yd/Gqb1ToiYSuL1FYoOLHgsgA== X-Received: by 10.194.21.99 with SMTP id u3mr2226513wje.0.1453735967894; Mon, 25 Jan 2016 07:32:47 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.25.83.211 with SMTP id h202ls467492lfb.51.gmail; Mon, 25 Jan 2016 07:32:46 -0800 (PST) X-Received: by 10.25.168.15 with SMTP id r15mr5269978lfe.166.1453735966068; Mon, 25 Jan 2016 07:32:46 -0800 (PST) Original-Received: from plane.gmane.org (plane.gmane.org. [80.91.229.3]) by mx.google.com with ESMTPS id l2si10094197lbc.182.2016.01.25.07.32.45 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 25 Jan 2016 07:32:45 -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 1aNj8H-0000rD-5N for std-proposals@isocpp.org; Mon, 25 Jan 2016 16:32:45 +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 ; Mon, 25 Jan 2016 16:32:45 +0100 Original-Received: from mwoehlke.floss by tripoint.kitware.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 25 Jan 2016 16:32:45 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 33 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:24011 Archived-At: On 2016-01-25 10:13, Ville Voutilainen wrote: > On 25 January 2016 at 16:26, Matthew Woehlke wrote: >>> Presumably tuple_size would be defined for mpl::vector the same way it is >>> for std::tuple. >> >> std::tuple *is fixed size*. I am not familiar with mpl::vector, but >> looking at >> http://www.boost.org/doc/libs/1_59_0/libs/mpl/doc/refmanual/vector.html, >> it certainly does not appear to be fixed size. > > Zomg wtf, mpl::vector is not only fixed size, but also immutable. > You can't change its size, the way append works in mpl is that it > gives you a completely new type, that is, it's completely pure with > no side-effects. Bah. Okay, that's what I get for skimming the doc :-). (Y'know, you could be polite and reply to the "am I missing something" part of my previous post...) But if that's the case, then what's the problem here? Arthur originally said: On 2016-01-20 18:13, Arthur O'Dwyer wrote: > would [mpl::vector] *not* be "tuple-like" because you couldn't use > std::get on it at runtime? ....but then, I don't understand why that would be true? Back to that question, yes, the idea as I understand it is that "tuple-like" <=> "can use get". Why is that an issue? -- 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/. .