220 18267 <1475047.29H4MbYzDs@tjmaciei-mobl4> article Path: news.gmane.org!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Core Language feature: Multiple assignments from multiple return values via tuple Date: Wed, 27 May 2015 15:55:51 -0700 Lines: 41 Approved: news@gmane.org Message-ID: <1475047.29H4MbYzDs@tjmaciei-mobl4> References: <69a59613-6504-466a-9878-786653d6087f@isocpp.org> <476a56f8-8313-4b94-9cb7-628ff52ac803@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 1432767364 26244 80.91.229.3 (27 May 2015 22:56:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 27 May 2015 22:56:04 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRB6UWTGVQKGQEZFMKUUI@isocpp.org Thu May 28 00:55:57 2015 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 1YxkEu-0003Cc-Ly for gclcip-std-proposals@m.gmane.org; Thu, 28 May 2015 00:55:56 +0200 Original-Received: by lbcak1 with SMTP id ak1sf6070493lbc.2 for ; Wed, 27 May 2015 15:55:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:user-agent :in-reply-to:references:mime-version:content-type:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=kTLaa2TgPN6POYCIHG9H1plp8GUASHmfcrmxk2MC1KE=; b=b2WrZAjQEjfCgU45DTqcBBBtx6rKG1esT83bfciAcn7oOlcgHALkpfeVnXv2Hl6ktv BDeBOzlfQwdPiQLnRy8EQ+Gl4zkWcjgd7xcli17hPKO4ZkdPW0kfJJNVk6Zlg7WV5Mo+ 8N2LQTjq0dWblZ6Y/oR2mU4NFCksCc94u7rmMs8CdKmN/lDPdH06z0/5krgvQlhXp03H 7A94LmOfVDIHiyv+EnZTEqZXushWo+gyMLtdgq8vOknINopkhGvrfuNiFaVoXqZakg3i w0X72bpUfGs3M9K6FvAU8BRcYjHHpxaqA06mqR1/sTgLVZgOwVXPFdB00Q4Pl+8p8V2T xUwA== X-Gm-Message-State: ALoCoQn9/QLZylWmKBkfucx6ErYtjRKdF2vBFy43LHB8delQzANzDQy6XkPe/eAVr182NcFtrQsJ X-Received: by 10.112.93.203 with SMTP id cw11mr34136730lbb.0.1432767356015; Wed, 27 May 2015 15:55:56 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.78.169 with SMTP id c9ls47801wix.3.gmail; Wed, 27 May 2015 15:55:54 -0700 (PDT) X-Received: by 10.194.143.75 with SMTP id sc11mr61399717wjb.62.1432767354535; Wed, 27 May 2015 15:55:54 -0700 (PDT) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [2a01:4f8:d13:f81:21c:14ff:fe01:12a3]) by mx.google.com with ESMTP id di1si669885wjb.37.2015.05.27.15.55.54 for ; Wed, 27 May 2015 15:55:54 -0700 (PDT) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) client-ip=2a01:4f8:d13:f81:21c:14ff:fe01:12a3; Original-Received: from tjmaciei-mobl4.localnet (jfdmzpr03-ext.jf.intel.com [134.134.139.72]) by gondolin.macieira.info (Postfix) with ESMTPSA id 9449911A5C8 for ; Wed, 27 May 2015 15:55:53 -0700 (PDT) User-Agent: KMail/4.14.6 (Linux/4.0.3-1-desktop; KDE/4.14.6; x86_64; ; ) In-Reply-To: <476a56f8-8313-4b94-9cb7-628ff52ac803@isocpp.org> X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) smtp.mail=thiago@macieira.org 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:18267 Archived-At: On Wednesday 27 May 2015 15:09:33 Nicol Bolas wrote: > We do have a similar concept: template parameter packs. It is one entity > which represents multiple objects. You can unpack them in arbitrary > expressions, which makes them much more useful than your limited `unpack` > tuple suggestion. Actually, thinking about it and fold expressions allows for very easy unpacking. The unpack-tuple-and-call function would be: template auto unpack(F &&f, std::tuple &&args) { using namespace std; return f(std::forward(get(args)), ...); } So all we need is for the MRV pack to be treated like a template parameter pack and we can use all the expansion tricks. std::cout << ... << args << endl; size_t sum = 0 + ... + args; // assuming they cast somehow to integer tuple t = make_tuple(..., args); If you have a template pack containing an MRV pack, you'll need the ....... operator... -- Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center PGP/GPG: 0x6EF45358; fingerprint: E067 918B B660 DBD1 105C 966C 33F5 F005 6EF4 5358 -- --- 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. 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