220 30229 <3252047.kbLLhmVhCu@tjmaciei-mobl1> article Path: news.gmane.org!.POSTED!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: enum_cast proposal Date: Wed, 04 Jan 2017 12:33:18 -0200 Lines: 41 Approved: news@gmane.org Message-ID: <3252047.kbLLhmVhCu@tjmaciei-mobl1> References: <6951935.9LYeBEmE6C@tjmaciei-mobl1> <8e7586fb-a121-4045-8f1e-a1399e229521@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1483540426 23102 195.159.176.226 (4 Jan 2017 14:33:46 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 4 Jan 2017 14:33:46 +0000 (UTC) User-Agent: KMail/5.3.3 (Linux/4.8.13-1-default; KDE/5.28.0; x86_64; ; ) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBSEPWTBQKGQEV6PU6CA@isocpp.org Wed Jan 04 15:33:41 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oi0-f70.google.com ([209.85.218.70]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cOmdI-0005Fc-KX for gclcip-std-proposals@m.gmane.org; Wed, 04 Jan 2017 15:33:40 +0100 Original-Received: by mail-oi0-f70.google.com with SMTP id n184sf1029367894oig.1 for ; Wed, 04 Jan 2017 06:33:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:user-agent:in-reply-to:references :mime-version:content-transfer-encoding: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=gkS1dZguJtWiJMaYwUYrvzLCqlI06sOw1mZrNVIUIh8=; b=ncXsna9f/ukigaV5RAbORK7vs1rs45IMzXaW+DG95vce88piU+JauanzWsp5LR7U7j oH3UOEYm+LSXGfNx0Z3C1N+EL/bZix+PHhVYjvu0TzS6Uh9ryynigmlTmyyd1Nab5d3u 19WjGGuGFCr8ACAskXImbVkW/qiFMVNjpCFEI2gl42tx4EzxauLGeg4iFo92myjmMYo8 ZB4HJBAsh5HJCFoxuwENZXIGEBdYyBuPLxWXgeMre50APVLlqQjmH+WE8Dh31gQO7JAx LH4qKZ9Ndx4tKo5wONYSKdv5ULaV64wXTmMZyrL0tTGhYrUXLAJaEMKjQR6ueaoij9yh X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:user-agent :in-reply-to:references:mime-version:content-transfer-encoding :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=gkS1dZguJtWiJMaYwUYrvzLCqlI06sOw1mZrNVIUIh8=; b=Y4kt9x6LwTgmD7TdzXlouo5dQ4sz3akysfg0gCHuw+Gz+gA5DXdb11/wLcoZbFcbIo aH6j7zLWzqGBi6mHsH1Oe6xfXe7TlzPB7hXtWo8wwczgqXYg1FdKZSGI2tZZ67KgcE8I J/OKTES853lUp0EqyclvPbqUUq6Q/qN9t3tYYPqaTdIUlESwufYT6c+SRdtVZxNoZuGx 6ANReFRLrQAVtxI8dpWzerPgPhWpBrrEL9x/ybucdc6bj2rfKJfFu+F2LmqTNHGzlcRx cCNkAlnHXmAXN+x152L71rrDjv6/djC+M+z6bIkcvoVZK464RMIJv0/Ox3r/pxHksEEE X-Gm-Message-State: AIkVDXLy7d8LeE1ZKgC1rj8XOx/Am3XS2AmkUlwsowZq9ihsMdnPzChoH7WMmyx0bmbNQw== X-Received: by 10.157.60.175 with SMTP id z44mr21000821otc.77.1483540424740; Wed, 04 Jan 2017 06:33:44 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.27.206 with SMTP id v14ls41535005otv.2.gmail; Wed, 04 Jan 2017 06:33:44 -0800 (PST) X-Received: by 10.237.42.108 with SMTP id k41mr60971446qtf.21.1483540424122; Wed, 04 Jan 2017 06:33:44 -0800 (PST) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [78.47.120.188]) by mx.google.com with ESMTP id k42si45324192qtk.83.2017.01.04.06.33.43 for ; Wed, 04 Jan 2017 06:33:44 -0800 (PST) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 78.47.120.188 as permitted sender) client-ip=78.47.120.188; Original-Received: from tjmaciei-mobl1.localnet (unknown [187.34.234.250]) by gondolin.macieira.info (Postfix) with ESMTPSA id 01A0811B7F3 for ; Wed, 4 Jan 2017 06:33:43 -0800 (PST) In-Reply-To: <8e7586fb-a121-4045-8f1e-a1399e229521@isocpp.org> X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 78.47.120.188 as permitted sender) smtp.mailfrom=thiago@macieira.org 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:30229 Archived-At: On ter=C3=A7a-feira, 3 de janeiro de 2017 19:43:33 BRST Nicol Bolas wrote: > > Anything that is a compiler feature (a builtin or a core language > > expression) > > needs to be able to choose between std::optional, > > std::experimental::optional > > and std::__1::optional by just changing #includes. >=20 > ... why? std::experimental::optional isn't part of the standard. And I ha= ve > no idea what `std::__1::optional` is. That's exactly the point: you don't know what the actual "optional" class's= =20 full name is. Therefore, a language feature should not reference a strict= =20 class name. I know std::initializer_list has already broken this rule but there were=20 mitigating factors: 1) it's a class that only the compiler can create in the first place 2) it didn't exist prior to the feature that referenced it, so compiler an= d=20 library writers could cooperate, unlike optional 3) there aren't many ways to store an array of items, but there is a=20 discussion on how to store a type and its presence flag Ditto for std::type_info. --=20 Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center --=20 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 e= mail 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/3252047.kbLLhmVhCu%40tjmaciei-mobl1. .