220 29153 article Path: news.gmane.org!.POSTED!not-for-mail From: "'Johannes Schaub' via ISO C++ Standard - Future Proposals" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Initializer list for move-only types Date: Thu, 27 Oct 2016 09:07:44 +0200 Lines: 116 Approved: news@gmane.org Message-ID: References: <34f09dd5-e231-4a0b-a218-48c8eabe73c5@isocpp.org> <6030c88d-626c-4cf9-a0e6-963ae3fbe708@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=001a1143d52002d3ca053fd3660a X-Trace: blaine.gmane.org 1477552524 18494 195.159.176.226 (27 Oct 2016 07:15:24 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 27 Oct 2016 07:15:24 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCQPNCEZSQNBBQWPY3AAKGQE6VX4OBA@isocpp.org Thu Oct 27 09:15:18 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw0-f200.google.com ([209.85.161.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bzetd-0007sw-Sq for gclcip-std-proposals@m.gmane.org; Thu, 27 Oct 2016 09:14:42 +0200 Original-Received: by mail-yw0-f200.google.com with SMTP id u124sf1547165ywg.3 for ; Thu, 27 Oct 2016 00:14:44 -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=VJ+A2xoqm7AHDYag98zNmjN65+qvF5CYQ2E0HV806DU=; b=gSWfmfFI73wbNHW1+yAp8BwpRLX5f9xqnq9E8JIqlCvsk7B5BmFbV8vxEmywUkp/j+ nVna3AaVxhjT9RPpwKDR3rd0bQe40GW5GJ2fUuz3xQHUAK7K1hb5TZ3W1eihyJy/aGMN LCijyKmVCoY7f9+dBagl8xWUFgQdOjUUsUm7No1BT+6t1+C0wgATLg7byM4bXuPu5KL6 NzP6kW5LUKOl6bfwmuqLHF506V+7IWnuaAQMqAerZyOnkpihWNH2OAZXRovq5LXb341e dvGszLV/yLA95hcw/4xj3xNm+fSWJRTPD42aUMGJJkmR9uJZUAWaRXIyUQsY4d0AiWFA 5f6w== 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=VJ+A2xoqm7AHDYag98zNmjN65+qvF5CYQ2E0HV806DU=; b=Rqg/s/kha0YPz/1WMB8Tu+4UGjqLs7wMnT96OZuf1g30x0fAVHmlhQc8ImEXcB6pOL SDLxlYj0OzN44ANpTTzPBBmRP5ojABIOMnJ/wISal/j4mZIzc3qFFx5zs1tLaDy1K1PR wgUaF79/XeDOQGvXOOgZ0UL9eSv4pWVoEjUeK3wKm0r6nhR0q85aBT/xYkPtIferi0Ay vVe8FtIC4Ai2ZhC26FBdDKaAx077Ec5njkuJkjByepqeSpQCLD7kxdvAFacuCYCe6tkS /2yEoHHfMtazlyOSLlv1myTPHK4IR6UHw9ylalB8ecIKFRXc0aWq3pbPVB6HbNjaTav2 marQ== X-Gm-Message-State: ABUngvd3a8sOO8hn5i9RnKC465knd2KwMu+FIgcxlSe/mWz96XnFi3r3+g5+r8KL+R/Jng== X-Received: by 10.107.24.134 with SMTP id 128mr1932983ioy.85.1477552067353; Thu, 27 Oct 2016 00:07:47 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.32.231 with SMTP id x94ls2401893ota.4.gmail; Thu, 27 Oct 2016 00:07:46 -0700 (PDT) X-Received: by 10.129.93.86 with SMTP id r83mr5929437ywb.15.1477552066206; Thu, 27 Oct 2016 00:07:46 -0700 (PDT) Original-Received: from mail-yw0-x22f.google.com (mail-yw0-x22f.google.com. [2607:f8b0:4002:c05::22f]) by mx.google.com with ESMTPS id r9si2144814ywb.141.2016.10.27.00.07.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Oct 2016 00:07:46 -0700 (PDT) Received-SPF: pass (google.com: domain of schaub.johannes@googlemail.com designates 2607:f8b0:4002:c05::22f as permitted sender) client-ip=2607:f8b0:4002:c05::22f; Original-Received: by mail-yw0-x22f.google.com with SMTP id w3so32391056ywg.1 for ; Thu, 27 Oct 2016 00:07:46 -0700 (PDT) X-Received: by 10.36.72.7 with SMTP id p7mr9105333ita.82.1477552065660; Thu, 27 Oct 2016 00:07:45 -0700 (PDT) Original-Received: by 10.107.175.36 with HTTP; Thu, 27 Oct 2016 00:07:44 -0700 (PDT) Original-Received: by 10.107.175.36 with HTTP; Thu, 27 Oct 2016 00:07:44 -0700 (PDT) In-Reply-To: X-Original-Sender: schaub.johannes@googlemail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@googlemail.com; spf=pass (google.com: domain of schaub.johannes@googlemail.com designates 2607:f8b0:4002:c05::22f as permitted sender) smtp.mailfrom=schaub.johannes@googlemail.com; dmarc=pass (p=QUARANTINE dis=NONE) header.from=googlemail.com X-Original-From: Johannes Schaub 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:29153 Archived-At: --001a1143d52002d3ca053fd3660a Content-Type: text/plain; charset=UTF-8 Am 27.10.2016 08:27 schrieb "Ville Voutilainen" : > > On 27 October 2016 at 05:21, David Krauss wrote: > > Interesting trip report, but the objection is that it changes the > > meaning of existing cases. It's possible > > that a proposal for a movable_initializer_list that is used only if > > the traditional one can't would fare > > better, > > > > > > Are you referring to deduction of local variables, e.g. auto list = { > > "foo"s, "bar"s, "baz"s } or for ( auto && str : { "foo"s, "bar"s, "baz"s } > > )? > > > > Or something to do with overloading, e.g. std::vector< std::string > list { > > "foo"s, "bar"s, "baz"s }? > > > Neither. I'm referring to filling the functionality gap without > changing the meaning > of existing code, so that > > vector> vec{make_unique(42), make_unique(666)}; > > works but there's no change to any currently valid cases. > I don't see the utility of changing the meaning of deduction yet. I think in the deducing cases, we could stay with const shallow initializer list (if only for backward compatibility). However outside of those two examples, what are cases that change meaning, and what were the cases that caused evolution to reject the paper? It appears to me that even David himself doesn't know about them yet (?) -- 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/CANu6V4UtYph6qt0_251PaUjAHV4Py5TjeCXvL8qMix4zaYq8hw%40mail.gmail.com. --001a1143d52002d3ca053fd3660a Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Am 27.10.2016 08:27 schrieb "Ville Voutilainen" &l= t;ville.voutilainen@gmail.co= m>:
>
> On 27 October 2016 at 05:21, David Krauss <potswa@gmail.com> wrote:
> > Interesting trip report, but the objection is that it changes the=
> > meaning of existing cases. It's possible
> > that a proposal for a movable_initializer_list that is used only = if
> > the traditional one can't would fare
> > better,
> >
> >
> > Are you referring to deduction of local variables, e.g. auto list= =3D {
> > "foo"s, "bar"s, "baz"s } or for ( a= uto && str : { "foo"s, "bar"s, "baz"s= }
> > )?
> >
> > Or something to do with overloading, e.g. std::vector< std::st= ring > list {
> > "foo"s, "bar"s, "baz"s }?
>
>
> Neither. I'm referring to filling the functionality gap without > changing the meaning
> of existing code, so that
>
> vector<unique_ptr<int>> vec{make_unique<int>(42), ma= ke_unique<int>(666)};
>
> works but there's no change to any currently valid cases.
>

I don't see the utility of changing the meaning of deduc= tion yet. I think in the deducing cases, we could stay with const shallow i= nitializer list (if only for backward compatibility).

However outside of those two examples, what are cases that c= hange meaning, and what were the cases that caused evolution to reject the = paper? It appears to me that even David himself doesn't know about them= yet (?)

--
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