220 31502 <4238c4e6-51f5-4a2f-94c8-f61ca415e7e0@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: 3dw4rd@verizon.net Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: compressed std::bitset Date: Tue, 7 Mar 2017 21:23:38 -0800 (PST) Lines: 215 Approved: news@gmane.org Message-ID: <4238c4e6-51f5-4a2f-94c8-f61ca415e7e0@isocpp.org> References: <32cfea0a-7df8-47cf-47fd-549985f12295@wanadoo.fr> <06e829ca-417b-470c-95ca-c661e8752f79@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_12_1932790725.1488950618864" X-Trace: blaine.gmane.org 1488950628 5060 195.159.176.226 (8 Mar 2017 05:23:48 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 8 Mar 2017 05:23:48 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCS2FYFYXYEBBW5K73CQKGQEWSQI4QI@isocpp.org Wed Mar 08 06:23:42 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qk0-f200.google.com ([209.85.220.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1clU4a-00008u-Cu for gclcip-std-proposals@m.gmane.org; Wed, 08 Mar 2017 06:23:40 +0100 Original-Received: by mail-qk0-f200.google.com with SMTP id n141sf55896990qke.1 for ; Tue, 07 Mar 2017 21:23:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=1geA4qAxJ4Lv9cJES7XsuoCfop9jjvBCJGnCcVKpg7o=; b=JIkYSBklTUZC281TcNvE55LuMTWUpTTHzhMr29wdniDftpCsxKyIzy8CCBmUXOLaqr r0ck/X98Yt+wDlbyktJuSpyzQuFoYKwjm2rvUskpTau9GuMzAXFTcx8p1xeYV8cmuxAM tOWHHIMT3ypt8tVq7HDj7reex0TKgZpVQRuK3Cv9iOJAtG4doc5mpSHOkBOB2xRcsUX1 QPvUW3+hzm7Ft/dTu5Uwx0AR3EWr8WfDEnYHcKyyztOoCYQJq9JNsF7uX7UZy9ttKYCk KnCu8mIjkZdm+k9aw+/xss+UUrmHyqEJCAqDN4gDeLl6xg4qYdRqqObgxL7aAZHq4WhW Khuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; 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:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=1geA4qAxJ4Lv9cJES7XsuoCfop9jjvBCJGnCcVKpg7o=; b=BNsmOp/kAKXJO73PQ+uaDvattYaIiQDLfW0fH3XWvCMnJS+/GehNjq/C5Wp4CUf8hW kOOrGwfzbRt3S2tqEJWgq0AKoJWyvAVXvfDww855GEi+Yua5cNF4UZFh4ns2XlAVx9tX 3AwMw6pvptj6eOX4xhg4evrbYjown2YAY93mtafD6s4MBBhCGisG+ABWJHBmtA+Ux8Hy VMpn/WMOycwQYA+0mA4sy2Dt43sb/qROSe7wEud7EWwaR8Z6vRo1pHSxQFlibWLjG11A pEisIfOWrfTllYuTu+uv+ge6wr3/qX6fE89xVMMaA6bihgZL1hl399BnQiDYGUMwH0qe 4dqQ== X-Gm-Message-State: AMke39lk1wKUa2HyyLhfq5hilEYCf4naKYbVOLXBv6aYAwE02Bct0hPPvLqEljqMQl5NpA== X-Received: by 10.200.56.211 with SMTP id g19mr1047761qtc.6.1488950620257; Tue, 07 Mar 2017 21:23:40 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.53.6 with SMTP id o6ls2347024otc.47.gmail; Tue, 07 Mar 2017 21:23:39 -0800 (PST) X-Received: by 10.157.22.200 with SMTP id s8mr562320ots.16.1488950619550; Tue, 07 Mar 2017 21:23:39 -0800 (PST) In-Reply-To: <06e829ca-417b-470c-95ca-c661e8752f79@isocpp.org> X-Original-Sender: 3dw4rd@verizon.net 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:31502 Archived-At: ------=_Part_12_1932790725.1488950618864 Content-Type: multipart/alternative; boundary="----=_Part_13_552856765.1488950618864" ------=_Part_13_552856765.1488950618864 Content-Type: text/plain; charset=UTF-8 On Tuesday, February 21, 2017 at 3:40:00 PM UTC-5, ricky6565 wrote: > > Hi Vicente, > > I think the Bitset2 library by > Claas Bontus provides what you are looking for. It's like std::bitset but > with enhanced functionality. It let's you set the underlying integral type > of the bitset. In fact, it defaults to uint8_t, uint16_t, or uint32_t if N bits > fit into those integers. I would like this functionality added to > std::bitset but, as you said, it would probably be a breaking change. > > Riccardo > I was just thinking something similar. Allow the user to specify the bitset leaf-type: template::digits> class bit_array { // pretty much like bitset except I would add using leaf_type = LeafTp; leaf_iterator lbegin() // leaf_iterator lend(); // }; This is flipped relative to Bitset2 in that leaf type comes first and the template would decide how many leaves based on bits. So now you could get these small bitsets: using bitset16 = bit_array; etc. I've heard people want similar choices for a dynamic_bitset: template class bit_vector { // pretty much like bitset except I would add using leaf_type = LeafTp; leaf_iterator lbegin() // leaf_iterator lend(); // }; People who do encryption wanted to set the size of the leaf and have access to leaves. I chose bit_array and bit_vector to have a similar relationship as array and vector do. -- 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/4238c4e6-51f5-4a2f-94c8-f61ca415e7e0%40isocpp.org. ------=_Part_13_552856765.1488950618864 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Tuesday, February 21, 2017 at 3:40:00 PM UTC-5,= ricky6565 wrote:
Hi Vicente,

I think the Bitset2 library by = Claas Bontus provides what you are looking for. It's like std::bitset b= ut with enhanced functionality. It let's you set the underlying integra= l type of the bitset. In fact, it=C2=A0= defaults to uint8_t, uint16_t, or uint32_t=C2=A0if N=C2=A0bits f= it into those integers.=C2=A0I would like this functionality added t= o std::bitset but, as you said, it would probably be a breaking change.

Riccardo

= I was just thinking something similar.=C2=A0 Allow the user to specify the = bitset leaf-type:

template<typename Le= afTp =3D unsigned long long, std::<= /span>size_t Bits =3D std::numeric_limits<LeafTp>::digits>
=C2=A0 class bit_array
=C2=A0 {
=C2=A0 =C2=A0 // pretty much like bitset except I would add
=C2=A0 =C2=A0 using leaf_type =3D LeafTp;
=C2=A0 =C2=A0 leaf_iterator lbegin() //
=C2=A0 =C2=A0 leaf_iterator lend(); //
=C2=A0 };


This is flipp= ed relative to Bitset2 in that leaf type comes first and the template would= decide how many leaves based on bits.

So now you could get these sm= all bitsets:
using bitset16 =3D bit_array<uint16_t>;
etc.
I've heard people want similar choices for a dynamic= _bitset:
template<typename LeafTp =3D unsigned long long>=
=C2=A0 class bit= _vector
=C2=A0 {<= br>=C2=A0 =C2=A0 // pretty much like bitset except I would add
=C2=A0 =C2=A0 using leaf_type =3D LeafTp;
=C2=A0 =C2=A0 leaf_iterator lbegin() //
=C2=A0 =C2=A0 leaf_iterator lend(); //
=C2=A0 };

People who do encrypt= ion wanted to set the size of the leaf and have access to leaves.
I chos= e bit_array and = bit_vector to ha= ve a similar relationship as array and = vector do.

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+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/4238c4e6-51f5-4a2f-94c8-f61ca415e7e0= %40isocpp.org.
------=_Part_13_552856765.1488950618864-- ------=_Part_12_1932790725.1488950618864-- .