220 24202 article Path: news.gmane.org!not-for-mail From: "'Edward Catmur' via ISO C++ Standard - Future Proposals" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Proposal: Change the specified behavior when control flow reaches the end of non-void functions Date: Thu, 4 Feb 2016 23:47:35 +0000 Lines: 114 Approved: news@gmane.org Message-ID: References: <5115b78c-8fb4-4c72-a278-f74c636f5217@isocpp.org> <2511401.bv6yOhHB5J@tjmaciei-mobl4> <1851432.TiVlt5xrhH@tjmaciei-mobl4> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=001a113ea6c2e47c55052afa5b6a X-Trace: ger.gmane.org 1454629660 11961 80.91.229.3 (4 Feb 2016 23:47:40 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 4 Feb 2016 23:47:40 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDZLZTXF7UJBBF6GZ62QKGQE5RVWEGA@isocpp.org Fri Feb 05 00:47:40 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-io0-f200.google.com ([209.85.223.200]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aRTcf-0006VT-Pk for gclcip-std-proposals@m.gmane.org; Fri, 05 Feb 2016 00:47:37 +0100 Original-Received: by mail-io0-f200.google.com with SMTP id o62sf157646703ioi.3 for ; Thu, 04 Feb 2016 15:47:37 -0800 (PST) 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:date:message-id:subject:from:to :content-type: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=jeY2ndzi0MXZrlH95R7ULUfrc2R1KHr0dQ/6ZxTaCGY=; b=pmlWn4unD9Rk4yCrKNlJ0F7PPK1I/w6sZdW8jflZBDrufEP5jfMCCMZaWX+BsrDK89 zlE7PakNRs41gYj2r365OV8/KVqU7NZejCWzZbgOkiQKp7aJEYMg2XiaPhuWNxu2mjM4 qMl824Hw55LKNWvvuCBVyWqTNrnZOFdgIzGZAIxqVCg0x2/dZdtWbEjm2rhPym1OblbC GDdo+dZp+jH3lWZ2XUFLlUwLsKFKHp8oFLeEJHco4L+UCccqYFx8ZIIc9Vtt2tawQ2+j qE2nENYdvddqO5dQvYsnCNCu1Zi2Y3/6hhkupfEcUL8gBxDJLBwZFG3M3WDihhOOuF8s LxOQ== 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:date :message-id:subject:from:to:content-type: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=jeY2ndzi0MXZrlH95R7ULUfrc2R1KHr0dQ/6ZxTaCGY=; b=XTi5tS6/QF1a6IYpLPG4YvCrGH1p2CW8IJSjQNafBvWpxtX2TCfnrskCKanugbOUnt MqkNW40dZJdCo4DM4fOGTTUambDolLYgF2RExYPp11HZD6b624+gM0Lq/ilGdNX6aM48 s7TVUp2VTOBogKtwZOKvDJTy71VKLkoUqJw+AF5mmjiLaI3gcvTvaTgqPax6cmYn7o+s P2VdogtK9dC4PRNWHM3L2M2uRMw6L/xQlaZ4WPyF6YqQKSt6gcZn9Ym3oGFVCYQK/wlM eCHgKvmOjXKllkwDIukBm5IUBfzVRWO/VbsbU3Oea1S2AHjMMg0kFVLnr2h9WUh6Uhu0 DPwg== X-Gm-Message-State: AG10YOS5QFlwiROeA5yVNN3TOJY7bq1Rr/88cW4w2toiPomq2oKcmKKOJW0HVXlfIkFz3Q== X-Received: by 10.182.56.233 with SMTP id d9mr9557825obq.2.1454629656558; Thu, 04 Feb 2016 15:47:36 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.107.26.202 with SMTP id a193ls270792ioa.87.gmail; Thu, 04 Feb 2016 15:47:35 -0800 (PST) X-Received: by 10.50.17.39 with SMTP id l7mr6976264igd.18.1454629655555; Thu, 04 Feb 2016 15:47:35 -0800 (PST) Original-Received: from mail-io0-x22f.google.com (mail-io0-x22f.google.com. [2607:f8b0:4001:c06::22f]) by mx.google.com with ESMTPS id h26si23314954iod.39.2016.02.04.15.47.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Feb 2016 15:47:35 -0800 (PST) Received-SPF: pass (google.com: domain of ecatmur@googlemail.com designates 2607:f8b0:4001:c06::22f as permitted sender) client-ip=2607:f8b0:4001:c06::22f; Original-Received: by mail-io0-x22f.google.com with SMTP id g73so111543983ioe.3 for ; Thu, 04 Feb 2016 15:47:35 -0800 (PST) X-Received: by 10.107.3.79 with SMTP id 76mr11443356iod.101.1454629655441; Thu, 04 Feb 2016 15:47:35 -0800 (PST) Original-Received: by 10.36.124.76 with HTTP; Thu, 4 Feb 2016 15:47:35 -0800 (PST) In-Reply-To: X-Original-Sender: ecatmur@googlemail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of ecatmur@googlemail.com designates 2607:f8b0:4001:c06::22f as permitted sender) smtp.mailfrom=ecatmur@googlemail.com; dkim=pass header.i=@googlemail.com; dmarc=pass (p=QUARANTINE dis=NONE) header.from=googlemail.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: , X-Original-From: Edward Catmur Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:24202 Archived-At: --001a113ea6c2e47c55052afa5b6a Content-Type: text/plain; charset=UTF-8 On Thu, Feb 4, 2016 at 11:32 PM, Ville Voutilainen < ville.voutilainen@gmail.com> wrote: > On 5 February 2016 at 01:25, 'Edward Catmur' via ISO C++ Standard - > Future Proposals >> > > The information loss is not a requirement. The > runtime could print the > >> > > reason > >> > > for termination before termination. > >> > > >> > How? std::terminate_handler is specified as void(*)() so there's > nowhere > >> > to > >> > pass in the reason. Existing terminate_handlers look at > >> > std::current_exception, so I suppose you could smuggle it in there, > but > >> > then you might as well throw that exception directly. > >> > >> Because the compiler does not need to directly call std::terminate. It > can > >> call a function of its own that prints the information, then calls > >> std::terminate. > > Thereby requiring that all C++ programs have a console attached, and > denying > > them control over what is output to that console? > > > Doing that does not in any way require a console to be attached, and > various > tools have been outputting such diagnostics into the standard error output > many > years. I don't quite grasp what you think is the problem here. Those tools are optional; they are not mandated by the standard. The problem is that you're proposing to terminate a program without giving the program itself any indication of why the termination is occurring; the only indication is a diagnostic emitted to a standard error output that may be discarded if it even exists at all. -- --- 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/. --001a113ea6c2e47c55052afa5b6a Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On T= hu, Feb 4, 2016 at 11:32 PM, Ville Voutilainen <ville.voutilaine= n@gmail.com> wrote:
On 5 Fe= bruary 2016 at 01:25, 'Edward Catmur' via ISO C++ Standard -
Future Proposals >> > > The information loss is not a requireme= nt. The
runtime could print the
>> > > reason
>> > > for termination before termination.
>> >
>> > How? std::terminate_handler is specified as void(*)() so ther= e's nowhere
>> > to
>> > pass in the reason. Existing terminate_handlers look at
>> > std::current_exception, so I suppose you could smuggle it in = there, but
>> > then you might as well throw that exception directly.
>>
>> Because the compiler does not need to directly call std::terminate= .. It can
>> call a function of its own that prints the information, then calls=
>> std::terminate.
> Thereby requiring that all C++ programs have a console attached, and d= enying
> them control over what is output to that console?


Doing that does not in any way require a console to be attached, and= various
tools have been outputting such diagnostics into the standard error output = many
years. I don't quite grasp what you think is the problem here.

Those tools are optional; they are not mandated by = the standard. The problem is that you're proposing to terminate a progr= am without giving the program itself any indication of why the termination = is occurring; the only indication is a diagnostic emitted to a standard err= or output that may be discarded if it even exists at all.
=

--

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To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+unsubscribe@isocpp.org.
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