220 34634 <85d58cac-6f09-42ca-b016-533ef1dbe6f1@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Omer Rosler Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: D0779R0: Proposing operator try() draft 1 paper Date: Thu, 5 Oct 2017 01:12:07 -0700 (PDT) Lines: 43 Approved: news@gmane.org Message-ID: <85d58cac-6f09-42ca-b016-533ef1dbe6f1@isocpp.org> References: <13df2242-f7dd-405d-b8b9-23b47981c56e@isocpp.org> <59D4D462.9040106@gmx.net> <602e9e20-1d2f-4545-be32-d0234639985c@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_9346_140099628.1507191127765" X-Trace: blaine.gmane.org 1507191128 10093 195.159.176.226 (5 Oct 2017 08:12:08 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 5 Oct 2017 08:12:08 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBC2L3NWCRYJBBWGS27HAKGQEECNAGBQ@isocpp.org Thu Oct 05 10:12:04 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pf0-f197.google.com ([209.85.192.197]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e01GE-00020X-Iw for gclcip-std-proposals@m.gmane.org; Thu, 05 Oct 2017 10:12:02 +0200 Original-Received: by mail-pf0-f197.google.com with SMTP id m28sf6199125pfi.17 for ; Thu, 05 Oct 2017 01:12:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=TNJPMrlAe7F+lBmV+AZs9rt5xVQ1A4Z8KzDnaz8dqi0=; b=CqiEq3TJYNG4tRqlqFTGX3rQDiUay1PLiJsK1UEBNIMGHbR2q8nWqBZPC5ebq10qpI 5hS6EwamT+apyANl6FDMJuqRmcIMMdHJgP8dz+CCqpgSE0Qr2VlkKe2DUB7aYY6/+QJ7 3zQ5D0IR1GRLg+xgTdxEOBS0FQKSs9kY2uVwyT+//5Pu0eUyhTVoXvn9f57fewmjmcf9 1BNd2D2uBKmADsfXCJyL0gDuPs3cQ2l+stOChM5igNHMn7BPWFcXorIxPW3ve6sLrViF BRP1oSUiFITXAjjI3yA1yZ1kO+HSUUsM5KdCI3HLmlHINr6XTtHqjFvkVJTZm1wZi3lu SQXQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=TNJPMrlAe7F+lBmV+AZs9rt5xVQ1A4Z8KzDnaz8dqi0=; b=I3TRQjEFDpemXdPht1UlzyF+gElB5DMhl/8jTcdI+m8Lq4ARB1PEWEKbM+7L9+mL6E 9Z/K/zd5bxWyBkoZIUuELNqA3IafEJuVtFMvdVjR8CO7KOeoUQZVWOuQD7MtvhYrZ2F/ 49PJoOKVv6qvjAdNTz4zyp/hPkYUrC3F3+MuL0PnjVdVioui0muhuH8eTFRUp35qRnvj TvHtNK9QbJaWhOtnNS2ZikTl9rm5I/KhlW+pZ5Dfa21OX2VjGf5H4777iVOAKfxvY7i7 /l+0QbCAxKr5iRD458HrlUoqVJpvXP/t1Ww8URN3vMEPGxullbYECqrzfq+74Ehx5auT Ny3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=TNJPMrlAe7F+lBmV+AZs9rt5xVQ1A4Z8KzDnaz8dqi0=; b=i4L/n41hXe6Fiz56tlzYgc2VGx9/65zUfDXZcOsOkRhDRq93ae0Mt32NZWL0CYL4qb zETxpcZ70z3e/4RXNncfK/3aekeQHhFPoQxAGXKOpRL3IkDGwG+j3SMjalSYUvlHoyny yRfDt39N+ebvLsGTq/Voj7ThBtfyq0puViwppogEoHkujv3ApFRapgmI11DmJzXCZ5Cz r5JbxVaOreIAcMQlHj1g9I7JxliT1Vf/EKU6OBssoraV+WuW5fPibXwiH1pKzHEOq+dH EbV+6vM6crIlTIw+GkqF/1GWH/LSqjkdNotIgjVb+PQNJQNgHlIbc/lWj7ad0cmGsshU CyKA== X-Gm-Message-State: AMCzsaW+YzPiRLVEeJHYbEEFVG/DeHR91jzkxRGKsEIGTNf8Rfcfikto mmKANCdqhCmvp+rvst4jaNAgUw== X-Google-Smtp-Source: AOwi7QAdVmDX83Y4wPQbG0kQYUqdhx5M3V1j95nXtBamyGQLO6dRK72QSRXRe87V+RdtCNf89tUk9g== X-Received: by 10.31.50.16 with SMTP id y16mr831784vky.30.1507191129641; Thu, 05 Oct 2017 01:12:09 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.159.54.83 with SMTP id s19ls5830535uad.2.gmail; Thu, 05 Oct 2017 01:12:08 -0700 (PDT) X-Received: by 10.31.180.22 with SMTP id d22mr1125128vkf.4.1507191128226; Thu, 05 Oct 2017 01:12:08 -0700 (PDT) In-Reply-To: X-Original-Sender: omer.rosler@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:34634 Archived-At: ------=_Part_9346_140099628.1507191127765 Content-Type: text/plain; charset="UTF-8" On Wednesday, October 4, 2017 at 5:54:36 PM UTC+3, Ville Voutilainen wrote: > On 4 October 2017 at 17:48, Nicol Bolas wrote: > >> Before we even go there, the paper needs to explain > >> > >> a) why this is a problem that needs to be solved > >> b) why it needs a language extension > >> > >> We can all see that it makes some code somewhere easier to write, and > >> we can grok that there are other > >> languages that have such a language facility. That alone doesn't > >> motivate a C++ language extension. > > > > > > Why it has to be a a language extension is easy: it's impossible to do it > > otherwise. > > That's great, but that explanation needs to be in the paper regardless of how > easy it supposedly is. > > > If you try to introduce a function that does what `try` does, it would be > > unable to do the one thing that makes `try` work: return. A function cannot > > force the calling function to return. You could make a macro that does what > > `try` does, but we have no way to do that within the language. > > Yes, well, perhaps we should look at adding something more general > than individual > keywords that perform specific transformations that then return (or > not) via a nettle bush > of traits and hooks. I wonder if we add such a language facillity, we could turn the Coroutine TS into a pure library extension? -- 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/85d58cac-6f09-42ca-b016-533ef1dbe6f1%40isocpp.org. ------=_Part_9346_140099628.1507191127765-- .