220 31258 article Path: news.gmane.org!.POSTED!not-for-mail From: Giovanni Piero Deretta Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: P0534: call/cc, type safety and exceptions Date: Wed, 1 Mar 2017 07:48:39 -0800 (PST) Lines: 71 Approved: news@gmane.org Message-ID: References: <3a57e294-7254-4358-828d-c9f7757f5295@isocpp.org> <4e6c13b2-4286-4df8-989b-97cbf3bf1cc7@isocpp.org> <312d04a6-8b20-4bf5-8357-507ba9938e84@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_1530_250009922.1488383319962" X-Trace: blaine.gmane.org 1488383324 5736 195.159.176.226 (1 Mar 2017 15:48:44 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 1 Mar 2017 15:48:44 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDEP3I7TGEINRWW3YUCRUBFCIRA2O@isocpp.org Wed Mar 01 16:48:39 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-io0-f198.google.com ([209.85.223.198]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cj6UV-0000SY-GO for gclcip-std-proposals@m.gmane.org; Wed, 01 Mar 2017 16:48:35 +0100 Original-Received: by mail-io0-f198.google.com with SMTP id 71sf49147063iol.2 for ; Wed, 01 Mar 2017 07:48:42 -0800 (PST) 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 :x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=aXsxfXR/5WFyHfzMgrMSWoLKumro0Sr9rqwwa9TA6zs=; b=XFiF5CRfnr3Y3EylH5raYF7iXKajpeNYIn2FeglYud2HNa4ek/c+Qw476o0aesiMsi j31kMqsPwPnQY9tPeyBfGkZcTLb2yZQzdHIvKzVbncbQOfQVC1JGXYK34demdvUmMQ4E j0+YqV4pkcutekSna3pCn/bAaSIvvBlufAPJkygidqTctIhfvOKPxl2es1snREGIsyQN rg8uQ88AR96BMJT9MTCOz2ztMJS3Nac4154ptAU6v/GYdeTas6rCnptUcdFE2f+MrLjm T954K1LXi7wU9WrdL3WyT+RQxZdbvhTBHhB0sBboNNZexs+Ae8ruYGGP0nzJimLD47iy gIrQ== 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 :x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=aXsxfXR/5WFyHfzMgrMSWoLKumro0Sr9rqwwa9TA6zs=; b=g3Z0q73u8ALcsMWY23mQYSdd2l6G3xbGOPlXqyEN711GCmnpfYvU1pzVSPFN2oyB1g UlXV3gwUIZ7DoUtjDKrQJe3TLnCtf6beZjY38SjSgW/gdt8haS5JvA5hz+7cEGONAsii x4T0h5puVde2zSKIq3iwZmaAjLUij7gDVNEJzad7K6O6KuZHHkbVqhQ7Do0XxIexr3am A5JMrTASmbkSVNgMdAwDvsHa/Ue7oWmfuaaXV92XF9cCJhLD+D+Py74O2bShx9dDQBQE gfdsvU+d5V8N28cgBm56Cm+E+2yJ3B2Wh/DZFnnNpbFdmrza791KV0bXFVJGzPIycAvP Ih8g== 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=aXsxfXR/5WFyHfzMgrMSWoLKumro0Sr9rqwwa9TA6zs=; b=h6ohDtESqVTDkCHxwxkU40tHkVMuBmW6Q5aqJ6BZwd/8RapXQ5lHVVPXM9sjUDqVtI 3o3n83i9FIY9YaAaElwlT4WZ4eThFzGQKLGAfuYWhS8CqD8RLrBwyU0NcFdGHreO1q5B aeNu2mMRTCqrmUXgxwABG8d3mspEQ6RWR1Uv/pZ7HnA3d7wHwh07sQCKiv8+yK4Vs4eG Dy/zwKo5/rRTBp4UpYtdqrierBv+x1BBYQXYJU1RW8weEExUxsVaMVu6g7ksbDrCJkga UjuFtGY4yuGgvwjF6PcMTPsx2fZIPTmNXPBGfd93qpAg+kZc09gkwYn8xjbK6vcUicBm o0PQ== X-Gm-Message-State: AMke39lx+RxRtXP0Wum9DvmIOfBxTvUDrt852SNb4AX/qOfJ8xvgNJ/G94FfNvIpMtz1Bg== X-Received: by 10.107.150.18 with SMTP id y18mr2669365iod.78.1488383321398; Wed, 01 Mar 2017 07:48:41 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.12.97 with SMTP id 88ls2966025otr.34.gmail; Wed, 01 Mar 2017 07:48:40 -0800 (PST) X-Received: by 10.157.17.114 with SMTP id p47mr1060731otp.6.1488383320489; Wed, 01 Mar 2017 07:48:40 -0800 (PST) In-Reply-To: <312d04a6-8b20-4bf5-8357-507ba9938e84@isocpp.org> X-Original-Sender: gpderetta@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:31258 Archived-At: ------=_Part_1530_250009922.1488383319962 Content-Type: multipart/alternative; boundary="----=_Part_1531_1149064119.1488383319963" ------=_Part_1531_1149064119.1488383319963 Content-Type: text/plain; charset=UTF-8 On Wednesday, March 1, 2017 at 3:38:13 PM UTC, Nicol Bolas wrote: [...] > > So we need the safe mechanism, and we need it shipped with the system. But > that should not be the *only* way; the lower-level form should still > exist. > > Now, maybe the type-safe version should be the *default*, so that if you > want the lower-level, unsafe API, we can clearly see that safety is being > sacrificed. So `callcc/continuation` would naturally be type-safe, with > `unsafe_callcc/unsafe_continuation` being not type safe. > we are in agreement then, I just want to point out that, given a type safe std::continuation implementation, the unsafe variant would simply be std::continuation, while the dynamic variant would be continuation, given a suitable implementation of any_ptr. -- 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/a3c76a9f-ef02-4ea7-a754-66ee5a95b38f%40isocpp.org. ------=_Part_1531_1149064119.1488383319963 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On Wednesday, March 1, 2017 at 3:38:13 PM UTC, Nicol Bolas= wrote:
[...]

So we need the safe mechanism, and we need it shipped wit= h the system. But that should not be the only way; the lower-level f= orm should still exist.

Now, maybe the type-safe version should be t= he default, so that if you want the lower-level, unsafe API, we can = clearly see that safety is being sacrificed. So `callcc/continuation` would= naturally be type-safe, with `unsafe_callcc/unsafe_continuation` bein= g not type safe.

we are in agreement t= hen, I just want to point out that, given a type safe std::continuation<= T> implementation, the unsafe variant would simply be std::continuation&= lt;void*>, while the dynamic variant would be continuation<std::any_p= tr>, given a suitable implementation of any_ptr.

--
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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.
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/a3c76a9f-ef02-4ea7-a754-66ee5a95b38f= %40isocpp.org.
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