220 29348 article Path: news.gmane.org!.POSTED!not-for-mail From: Andrey Semashev Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: std::byte thoughts Date: Wed, 2 Nov 2016 17:50:56 +0300 Lines: 23 Approved: news@gmane.org Message-ID: References: <7da80620-e4bd-40eb-a4ec-4f3c2dcb2c98@isocpp.org> <1549171.TC16PSHVVd@tjmaciei-mobl1> <2350841.Z7lUCKSumT@tjmaciei-mobl1> <3e64b220-79ae-4108-ba1c-9785494fc434@isocpp.org> <97ebfc84-c5a3-eaf5-efcb-c1bdf9b507a5@gmail.com> <5933359a-3f59-33df-10db-e643bfa39c55@honermann.net> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed X-Trace: blaine.gmane.org 1478098300 27118 195.159.176.226 (2 Nov 2016 14:51:40 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 2 Nov 2016 14:51:40 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCXY5TXHWYJRBU7247AAKGQEYSEV2YQ@isocpp.org Wed Nov 02 15:51:36 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wm0-f71.google.com ([74.125.82.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1c1wsT-0002AP-U7 for gclcip-std-proposals@m.gmane.org; Wed, 02 Nov 2016 15:50:57 +0100 Original-Received: by mail-wm0-f71.google.com with SMTP id l124sf12100991wml.4 for ; Wed, 02 Nov 2016 07:51:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-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=jWSn9tDwKiGjHEE8e7Dxc/ye5m1bNWuuiMDgP1WkzLc=; b=ITpfdwTf+vkKtvWguOhgntLYRS0X7s54Bvbubhbba1ks5hOAJU8YQf4UMoGNX/LIrb AEtyIyFFvuZxu076LsYqe7oh2hlNqgvgWhqyclVlBYDZuYDu+1fgORijVmlck7cF/ssx TaIiM5uEf7jt3v0Wxshf+N4r5buVvi6LZlxTmWmhE7eMxESkoQ1sN+1ps6+xHgWZg4mH zt4f7I9ilQxJw94hcwAoV9jsT00DvPC+Pq32KfABf1eaF/GOpSk8EmkhOYrAWXM7Acak l2ku4xcuVMpSzbnbr2aync7kVco7ZSO+3WmF7n92Oei5wQm9y+h2b5KnnFi6bihLzSaT XgCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-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=jWSn9tDwKiGjHEE8e7Dxc/ye5m1bNWuuiMDgP1WkzLc=; b=YqNeAdTVV+XWSvi6e37qjE+KIeMAwYyDR/D7HQYdMqhyGA4y1RSJqBrtXKI7cfizPg DbgxHJM8b6F6+c1gmkp/urgXaaQPM43ZrTT3TpXYezxAKKG3GR6jocXUioOCJUX2b5PN to6eM2LYnEfraJ5VmOpzvNw8lMfKERaMReCJ3xevOmR65cjwL+SqsK1DAA4YjeZBgVJo e9ecY3fwwd1Cgh+eLwKN1D0BvZ3yZ3MhmVsQLIj38v5qwb1xdeqfIrHBauHJlO9kdmjZ 2WN67LQb/n8B7UlBVF1UzJ6wvq42kYRr38zb9tuADmvbHdthel4tYyZ9jYvVm1qRcvpc 8u1g== X-Gm-Message-State: ABUngveLDXONIHd4WYrq51cbsbyULtgA2GYt2nEkJ7n5UzV+/cVTF5a8IsfhinekzHKD/w== X-Received: by 10.28.197.6 with SMTP id v6mr435020wmf.13.1478098260539; Wed, 02 Nov 2016 07:51:00 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.25.215.164 with SMTP id q36ls545907lfi.16.gmail; Wed, 02 Nov 2016 07:50:58 -0700 (PDT) X-Received: by 10.25.125.84 with SMTP id y81mr1993542lfc.37.1478098258902; Wed, 02 Nov 2016 07:50:58 -0700 (PDT) Original-Received: from mail-lf0-x22a.google.com (mail-lf0-x22a.google.com. [2a00:1450:4010:c07::22a]) by mx.google.com with ESMTPS id n76si1695474lfi.40.2016.11.02.07.50.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Nov 2016 07:50:58 -0700 (PDT) Received-SPF: pass (google.com: domain of andrey.semashev@gmail.com designates 2a00:1450:4010:c07::22a as permitted sender) client-ip=2a00:1450:4010:c07::22a; Original-Received: by mail-lf0-x22a.google.com with SMTP id t196so14838417lff.3 for ; Wed, 02 Nov 2016 07:50:58 -0700 (PDT) X-Received: by 10.25.163.132 with SMTP id m126mr2415314lfe.9.1478098258278; Wed, 02 Nov 2016 07:50:58 -0700 (PDT) Original-Received: from [192.168.1.2] (broadband-90-154-68-136.nationalcablenetworks.ru. [90.154.68.136]) by smtp.googlemail.com with ESMTPSA id o194sm530069lfo.42.2016.11.02.07.50.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Nov 2016 07:50:57 -0700 (PDT) In-Reply-To: <5933359a-3f59-33df-10db-e643bfa39c55@honermann.net> X-Original-Sender: andrey.semashev@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of andrey.semashev@gmail.com designates 2a00:1450:4010:c07::22a as permitted sender) smtp.mailfrom=andrey.semashev@gmail.com; dmarc=pass (p=NONE dis=NONE) header.from=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:29348 Archived-At: On 11/02/16 17:01, Tom Honermann wrote: > On 11/02/2016 05:02 AM, Andrey Semashev wrote: >> Assuming that code units are always positive (which I don't think is >> mandated anywhere, but let's keep things sane), > > I don't know of any encodings that specify negative values for code > units or code points. However, the mapping of UTF-8 code units to char > results in negative code unit values in UTF-8 strings for > implementations that use a signed 8-bit char. So, in practice, sanity > does not always prevail. This is one of the motivations for P0482R0 > . AFAIR, Unicode does not define negative code units. The fact that code units greater than 0x7f cannot be represented in 8-bit signed `char` simply means overflow and implementation-defined behavior. In other words, UTF-8 code units cannot be represented by `char` on such platforms. -- 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/a6b76054-436c-9f0f-db6d-f93b95c63938%40gmail.com. .