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Botet Escriba" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Make (strongly typed) enums castable to char const * const Date: Wed, 31 Aug 2016 22:34:40 +0200 Lines: 42 Approved: news@gmane.org Message-ID: <791a04ce-3dd7-fc31-8798-ee4fe812d7fb@wanadoo.fr> References: <878tvfl89r.fsf@gmail.com> 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 Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1472675704 29757 195.159.176.226 (31 Aug 2016 20:35:04 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 31 Aug 2016 20:35:04 +0000 (UTC) User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDH67CONY4PBBX76TS7AKGQENURBM5I@isocpp.org Wed Aug 31 22:35:00 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 1bfCDm-0006C9-Mr for gclcip-std-proposals@m.gmane.org; Wed, 31 Aug 2016 22:34:54 +0200 Original-Received: by mail-wm0-f71.google.com with SMTP id m139sf22290366wma.0 for ; Wed, 31 Aug 2016 13:34:56 -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: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=QI/29aOC26OKLxq/FAdZIrxb9wrqHR4Y+oS/FH/FTkE=; b=TXsROKUDDPIibBp43tKy47p6ViaeiPWnTN3/TVuywKcFhNZAYDux5jXqRfvJ5yqdHN CdhOGE0tofosL8mGIKw8pnwAlRCwmV+5jXZd9QDtapenn5XBPIm166M77IpxUtYKDdib KYFXLh4MYpl7bQ8bnZ+bycWyAdZGqaVxQkTtkGMctPMHtY88s/WBJrkqa/Y0oumQxyIY +fOLYyV/oMgH1IQaaTDWJ24iQjEt4uxZnrLFS1PoUh22/EfwYhfnatv7FgnRx4BsRath nIHREG48L0KJVi4C8zVevikuYNxPfvoGOqQLzDR+Gv/ncd8J2OcOJ+dHRAWhcf/cFdmH 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: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=QI/29aOC26OKLxq/FAdZIrxb9wrqHR4Y+oS/FH/FTkE=; b=H5UEQjlPQnbtlL6YI5smae2rMdQtWEIiCo4njuNLcUz6h6OYIcH3vd/GOf3MxROXUk nXIMxYNbvBkqZ6ueU/gWZjoJ67YGeezwEQHH/LOpm4x5zSRXC+WQamgf21RfoNbEiYnM 7EnQt8jCZGNinmIdIn3NpCmrMrsD8g6xDsfIuF+yHHZ2MHR+/oA/I2SAXO9+uFabkEWm aB+ifD6Xr4s7GRCeA/7+PBbMGpxDrOYAK25lQPoTSbhFAEix9LhWIBuF1FRhPATkUGRh eIe+AADw6OKZ7oQ743xlIWdsmd0SbSm6ywuIpFa4FdiOI/J73sA04WAYT+U3WQxEmzxh X-Gm-Message-State: AE9vXwMWQUtHTC9AiQmeehENauac1kQjiw0CdHu/SZtLrK03ll+lSuBkfx/3NO8QEAP2Yw== X-Received: by 10.194.119.105 with SMTP id kt9mr1786386wjb.1.1472675690756; Wed, 31 Aug 2016 13:34:50 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.28.164.132 with SMTP id n126ls1513010wme.1.gmail; Wed, 31 Aug 2016 13:34:37 -0700 (PDT) X-Received: by 10.28.98.135 with SMTP id w129mr11634561wmb.38.1472675676479; Wed, 31 Aug 2016 13:34:36 -0700 (PDT) Original-Received: from smtp.smtpout.orange.fr (smtp10.smtpout.orange.fr. [80.12.242.132]) by mx.google.com with ESMTPS id si1si1803243wjb.210.2016.08.31.13.34.36 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 31 Aug 2016 13:34:36 -0700 (PDT) Received-SPF: neutral (google.com: 80.12.242.132 is neither permitted nor denied by best guess record for domain of vicente.botet@wanadoo.fr) client-ip=80.12.242.132; Original-Received: from pc38.home ([2.13.33.56]) by mwinf5d33 with ME id dwaa1t00B1CfgbE03wabX0; Wed, 31 Aug 2016 22:34:36 +0200 X-ME-Helo: pc38.home X-ME-Auth: dmljZW50ZS5ib3RldEB3YW5hZG9vLmZy X-ME-Date: Wed, 31 Aug 2016 22:34:36 +0200 X-ME-IP: 2.13.33.56 In-Reply-To: X-Original-Sender: vicente.botet@wanadoo.fr X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 80.12.242.132 is neither permitted nor denied by best guess record for domain of vicente.botet@wanadoo.fr) smtp.mailfrom=vicente.botet@wanadoo.fr 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:28083 Archived-At: Le 31/08/2016 =C3=A0 02:59, Patrice Roy a =C3=A9crit : > An important issue I was trying to bring up (but failed :) ) is the=20 > handling of values from the underlying type that don't match effective=20 > enum values. C# does something, it might not be what we want, and what=20 > one of us wants does not necessarily match what another one of us wants. > > I think Edward saw this : the difficulty in making standard=20 > enum-to-string behavior is (a) what to do with values that don't map=20 > to an enum constant, and (b) choosing what to do with scope names=20 > (class, namespace, ...) with the relevant string values. These issues=20 > don't seem easy to settle in a standard fashion, at least in my eyes,=20 > as there are valid arguments for various behaviors. You are right that there are some variation points. (a) I believe the C# option is a good one. If the user wants to check=20 for validity of an enum constant another function can be provided and=20 the user could combine them. This is a subset of enums. (b) I believe that having the string for the enumerators is the minimal=20 feature and it is already beter than the number. We can as well have=20 another function that allows to obtain the string associated to the scope. > > Now, if someone could write a proposal that both offers language=20 > support for some behavior, and backs it up with library functions that=20 > let users control the conversion behavior efficiently, then... :) I hope that someone would propose something once we have reflection=20 delivered by a major compiler ;-) Vicente --=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/791a04ce-3dd7-fc31-8798-ee4fe812d7fb%40wanadoo.f= r. .