220 13407 article Path: news.gmane.org!not-for-mail From: Matthew Fioravante Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: constexpr ascii character checks Date: Tue, 30 Sep 2014 17:34:44 -0700 (PDT) Lines: 129 Approved: news@gmane.org Message-ID: References: <3848703.davq006XdY@tjmaciei-mobl4> <2650743.qSLh741pjc@tjmaciei-mobl4> <80b406dd-3327-4f39-a885-75ad6e692fef@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_5087_1792116971.1412123685062" X-Trace: ger.gmane.org 1412123694 6920 80.91.229.3 (1 Oct 2014 00:34:54 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 1 Oct 2014 00:34:54 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDELF54RTIGRBJUYVWQQKGQEGBEXNDA@isocpp.org Wed Oct 01 02:34:49 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ie0-f197.google.com ([209.85.223.197]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XZ7sV-0007AY-JY for gclcip-std-proposals@m.gmane.org; Wed, 01 Oct 2014 02:34:47 +0200 Original-Received: by mail-ie0-f197.google.com with SMTP id rp18sf329590iec.8 for ; Tue, 30 Sep 2014 17:34:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=uhAhz0AxBpgP1gxoKeI2p1+5frJZLPKMpwuBx7TEPkg=; b=PJpHOk8T58MvP5/T0imv20v823u0CWStdyI2J7BiXZ/oj0ki21zn4zPyOEaZ897g8o Q1AyzGVdSuwq9UV4iGraB6xvX0fpRSYXzP+6qHU8/DeSU9IO7lN2zZogrWr5AXoMBGVm kxRtiAyMK0jg0nnF1EpZlWeqeuUu/ZvX10UMids2OIIBYpQmR/k6QmeOacNUaW4y3X3T jtCNXZqGA8O5b6uUNtighaEo9ZAkoeJNMhGqecJPTX4D3DPM6fIroAytg4eseY6sPmXv JewW6NZotH/HY12aVEySeUPPmYmyLaKhQiPShpUMG/GcN2tBjtfoRAcYFx/+3MN7ozP7 rTTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; 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:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=uhAhz0AxBpgP1gxoKeI2p1+5frJZLPKMpwuBx7TEPkg=; b=glasb02mz1WAP4AfjaN47uaxbAYuzF6dJOM3tvAzhV20qFtBZSVAyE2dZVHFoCR+DL U1kBdnpyNdsCp3XCH99/MUgfZMQFbNKedV5jd4sBecgcQZC5nYWisyq5fhXC4V+M6oji RZEx4VXsel2dwp2LRlRrHgwFi9ar5kGxRzjWjF+DGNwstpCPeTY2ddZCQdtfCFzY6fN/ aQiM/bGLkR9ZWhcvC0Fw20qxOm7VM5m44wgfaCHsCtCx6g2heF8xNiVHfJtNgUjkc45x HMwDGfRzRN82yOUK/lXwMMnEBmyfmtK3e0mhC0s0hlSByuPFycGD//txtsSZPgXCVbzm SoNA== X-Gm-Message-State: ALoCoQlECeVLILJiHPgBYZVz3fazXfSll8wjwYCa4i6yLC/OjkYkAzUEFPJLLKcc9gPcJdWb6Hu8 X-Received: by 10.182.66.234 with SMTP id i10mr42956697obt.12.1412123686716; Tue, 30 Sep 2014 17:34:46 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.108.229 with SMTP id j92ls299998qgf.31.gmail; Tue, 30 Sep 2014 17:34:46 -0700 (PDT) X-Received: by 10.140.37.39 with SMTP id q36mr33036qgq.10.1412123686067; Tue, 30 Sep 2014 17:34:46 -0700 (PDT) In-Reply-To: <80b406dd-3327-4f39-a885-75ad6e692fef@isocpp.org> X-Original-Sender: fmatthew5876@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:13407 Archived-At: ------=_Part_5087_1792116971.1412123685062 Content-Type: text/plain; charset=UTF-8 On Tuesday, September 30, 2014 12:25:18 AM UTC-4, Myriachan wrote: > > On Saturday, September 27, 2014 6:35:15 PM UTC-7, Thiago Macieira wrote: >> >> On Saturday 27 September 2014 00:25:30 Myriachan wrote: >> > I meant that "int" can't necessarily hold char16_t and char32_t. >> >> I don't see how "int" got into the discussion. >> >> std::ascii::isxxx should take char, char16_t and char32_t. It stands to >> reason >> that you already know that a given character is ASCII before using the >> function. A wchar_t overload can be present only if the implementation >> knows >> at compile time that wchar_t is always a superset of ASCII. >> >> The use of int for ctype.h is an extreme legacy from C's obscure past. >> >> > His draft used "int"; that's why I mentioned it and pointed out why it's > problematic. > > https://github.com/fmatthew5876/stdcxx-ascii/blob/master/proposal/draft.html > > I originally proposed int so that the functions would be compatible with C getchar() and EOF. Looking at it again, perhaps that is not so necessary. I never use either of those and even if I did I would be doing an EOF check before passing it on to an ascii function. Setting the type to char also resolves ambiguities and questions about values that are valid for int but invalid for char (such as negative values). I've changed the proposal to accept char, char16_t, char32_t. A new version of the paper is available: https://github.com/fmatthew5876/stdcxx-ascii I'm still on the fence about wchar_t. While it looks like the direction is for wchar_t to eventually go away there are a lot of people using it. Windows developers being the prime example. Is anyone here a windows developer who would find these functions at all useful with wchar_t? Even if wchar_t is planned to be deprecated, we can still add overloads now and deprecate them later if and when wchar_t gets deprecated. -- --- 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 http://groups.google.com/a/isocpp.org/group/std-proposals/. ------=_Part_5087_1792116971.1412123685062 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Tuesday, September 30, 2014 12:25:18 AM UTC-4, = Myriachan wrote:
On Saturday, September 27, 2014 6:35:15 PM UTC-7, Thiago Macieira wrote:=
On Saturday 27 September 2014 00:25= :30 Myriachan wrote:
> I meant that "int" can't necessarily hold char16_t and char32_t.

I don't see how "int" got into the discussion.

std::ascii::isxxx should take char, char16_t and char32_t. It stands to= reason=20
that you already know that a given character is ASCII before using the= =20
function. A wchar_t overload can be present only if the implementation = knows=20
at compile time that wchar_t is always a superset of ASCII.

The use of int for ctype.h is an extreme legacy from C's obscure past.


His draft used "int"; that's why I mentioned it a= nd pointed out why it's problematic.
https://github.com/fmatthew5876/stdcxx-ascii/blob/master= /proposal/draft.html


I originally proposed int so that the functions would be compatible = with C getchar() and EOF. Looking at it again, perhaps that is not so neces= sary. I never use either of those and even if I did I would be doing an EOF= check before passing it on to an ascii function. Setting the type to char = also resolves ambiguities and questions about values that are valid for int= but invalid for char (such as negative values).

I= 've changed the proposal to accept char, char16_t, char32_t. A new version = of the paper is available:

https://github.com/fmat= thew5876/stdcxx-ascii

I'm still on the fence about wchar_t. W= hile it looks like the direction is for wchar_t to eventually go away there= are a lot of people using it. Windows developers being the prime example.<= /div>

Is anyone here a windows developer who would find = these functions at all useful with wchar_t? Even if wchar_t is planned to b= e deprecated, we can still add overloads now and deprecate them later if an= d when wchar_t gets deprecated.

--

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