220 13518 article Path: news.gmane.org!not-for-mail From: Farid Mehrabi Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Proposal: Strongly Typed Bitset Date: Thu, 2 Oct 2014 14:52:59 +0330 Lines: 154 Approved: news@gmane.org Message-ID: References: <113390b2-9c74-47e2-a943-5d27dd48bdf1@isocpp.org> <41983d24-efb2-4255-b09b-f84cff7bf56d@isocpp.org> <63de9d71-e3b0-4242-9698-bea3a307b3c7@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=bcaec53d5b1ff0562a05046ed74d X-Trace: ger.gmane.org 1412249010 18497 80.91.229.3 (2 Oct 2014 11:23:30 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 2 Oct 2014 11:23:30 +0000 (UTC) To: std-proposals Original-X-From: std-proposals+bncBC27JR6ERAOBBJ7LWSQQKGQE32WS45A@isocpp.org Thu Oct 02 13:23:25 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wg0-f70.google.com ([74.125.82.70]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XZeTg-0008E6-U5 for gclcip-std-proposals@m.gmane.org; Thu, 02 Oct 2014 13:23:21 +0200 Original-Received: by mail-wg0-f70.google.com with SMTP id a1sf1037089wgh.1 for ; Thu, 02 Oct 2014 04:23:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe:content-type; bh=+Ox5shnPufYtlsnU4TtciRKdEWz0BFwTP95HETaADzA=; b=QswmyrfzrB6cZ5Orsf2XglqZ5Tl+khWvEfsNPGH0AF3gwgPWGvyToGzbAjqwIbZpDk nFI84c74YY5M400p3v2jLlYJerAEWpiVS682LAQPLaPcdv4uum6PygrQVWeHiA29kZY5 3f4zaY4nsb9+Rrt/ZZlYTyPmx0sjOg9KCwjCG/xsPRdNlw5Goc+u//KHQKQb4NWsnBEN nZ0V7pBKp9McOpDEe1tEeX2qmKS9gDUvJMzrL/5/nDSOpavf1sXIZBiQUp4vi1A8M+i1 spphtqQsdGKUleZlHV2VAKpsFvRjMCfb7kdHAWyJvxFXjILNi1NeEbXErkUY0RHBYpS1 dAsA== X-Gm-Message-State: ALoCoQkRB3/7EDykrjG5XCeH5EgckKbmNM+9W2TzFM6h7/UQitm3Em8mXiYwHwEKDBTZqyfX/oSY X-Received: by 10.112.6.138 with SMTP id b10mr409316lba.18.1412249000607; Thu, 02 Oct 2014 04:23:20 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.126.105 with SMTP id mx9ls63882wib.53.gmail; Thu, 02 Oct 2014 04:23:19 -0700 (PDT) X-Received: by 10.180.95.163 with SMTP id dl3mr3161686wib.79.1412248999561; Thu, 02 Oct 2014 04:23:19 -0700 (PDT) Original-Received: from mail-wi0-x232.google.com (mail-wi0-x232.google.com [2a00:1450:400c:c05::232]) by mx.google.com with ESMTPS id er10si762824wib.88.2014.10.02.04.23.19 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 02 Oct 2014 04:23:19 -0700 (PDT) Received-SPF: pass (google.com: domain of farid.mehrabi@gmail.com designates 2a00:1450:400c:c05::232 as permitted sender) client-ip=2a00:1450:400c:c05::232; Original-Received: by mail-wi0-f178.google.com with SMTP id cc10so3677321wib.5 for ; Thu, 02 Oct 2014 04:23:19 -0700 (PDT) X-Received: by 10.180.20.139 with SMTP id n11mr3389008wie.22.1412248999317; Thu, 02 Oct 2014 04:23:19 -0700 (PDT) Original-Received: by 10.217.41.5 with HTTP; Thu, 2 Oct 2014 04:22:59 -0700 (PDT) In-Reply-To: X-Original-Sender: farid.mehrabi@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of farid.mehrabi@gmail.com designates 2a00:1450:400c:c05::232 as permitted sender) smtp.mail=farid.mehrabi@gmail.com; dkim=pass header.i=@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:13518 Archived-At: --bcaec53d5b1ff0562a05046ed74d Content-Type: text/plain; charset=UTF-8 2014-10-02 11:21 GMT+03:30 Nicola Gigante : > > Hi > > Il giorno 02/ott/2014, alle ore 03:26, Matthew Fioravante < > fmatthew5876@gmail.com> ha scritto: > > I've updated the draft with fast_bitset and small_bitset. > > https://github.com/fmatthew5876/stdcxx-bitset > > I had some ideas for additional directions to go into. I've not put these > in the paper. > > Some new public members: > > template class bitset { > public: > using underlying_type = T[N / (sizeof(T) * CHAR_BIT) + 1]; > > array get_underlying() const; > void set_underlying(array a); > > > I would rather : template class bitset { public: static constexpr size_t word_size = sizeof(T) * CHAR_BIT ; using underlying_type = T[ (N + word_size - 1) / word_size ]; that is more efficient; when (N % word_size) == 0, this approach will save us one unused extra word per instance. regards, FM -- --- 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. 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2014-10-02 11:21 GMT+03:30 Nicola Gigante <nic= ola.gigante@gmail.com>:

Hi

Il giorno 02/ott/2014, alle ore 03:26, Matthew Fioravante <fmatthew5876@gmail.co= m> ha scritto:

<= div dir=3D"ltr">I've updated the draft with fast_bitset and small_bitse= t.


I had some ideas for additional directions to go= into. I've not put these in the paper.

Some n= ew public members:

template <size_t N,<= /span> typename T> class bitse= t {
=C2=A0 public: =C2=A0
=C2=A0 =C2=A0 using u= nderlying_type =3D T[N /<= /span> (sizeof(T) * CHAR_BIT) + = 1];

=C2=A0 =C2=A0= array<T,sizeof(underlying_type) /<= font> sizeof(T)> get_underlying() const;<= /span>
=C2=A0 =C2=A0 void set_= underlying(array<T,sizeof(underlying_type) / sizeof(T)> a);
=C2=A0
=C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 I would rather :
template=C2=A0<size_t N,=C2=A0typename=C2=A0T<= span style=3D"color:rgb(102,102,0)">>=C2=A0class=C2=A0bitset=C2=A0{
=C2=A0=C2=A0public:=C2=A0=C2=A0
=C2=A0 =C2=A0 static co= nstexpr size_t word_size =3D=C2=A0sizeof(T)=C2=A0=C2=A0*=C2=A0=C2=A0CHAR_BIT=C2=A0;
<= code>=C2=A0 =C2=A0=C2=A0=C2=A0usi= ng=C2=A0underlying_type=C2=A0= =3D T[ (N +=C2=A0word_size=C2=A0- 1) / word_size ];

=C2=A0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0that is more efficie= nt; when (N %=C2=A0word_s= ize)=C2=A0=3D=3D 0= , this approach will save us one unused extra word per instance.
regards,
FM

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