220 34895 article Path: news.gmane.org!.POSTED!not-for-mail From: euloanty@live.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Thoughts on more methods towards containers in the future Date: Sat, 14 Oct 2017 06:27:44 -0700 (PDT) Lines: 126 Approved: news@gmane.org Message-ID: References: <973f04da-1354-44f4-9d1f-23f04596b8dc@isocpp.org> <20171014085305.GA24512@fukushima.lysator.liu.se> <79c51b8c-6cc2-4872-8651-9dae513d1e21@isocpp.org> <1550fc17-cf97-438d-9e7a-862f729adbf5@isocpp.org> <0cc942cf-a217-4175-98b0-b466ac224dc7@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_2293_1746173585.1507987664129" X-Trace: blaine.gmane.org 1507987678 11929 195.159.176.226 (14 Oct 2017 13:27:58 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 14 Oct 2017 13:27:58 +0000 (UTC) Cc: euloanty@live.com To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDPYX6PYRQNBBUFBRDHQKGQEDUJCLQA@isocpp.org Sat Oct 14 15:27:54 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ua0-f199.google.com ([209.85.217.199]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1e3MTf-0000Tb-K6 for gclcip-std-proposals@m.gmane.org; Sat, 14 Oct 2017 15:27:43 +0200 Original-Received: by mail-ua0-f199.google.com with SMTP id 65sf902223uaq.4 for ; Sat, 14 Oct 2017 06:27:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc: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; bh=c/7l8yWIlYmMwz+LdcKhsBHxlHiAA1PZlKFTvo8miXU=; b=z7NT75ehhyT7Vmr/2e2OA2+t4xTELGfucVFUQz8aqxxaffdLMg+H4QpbWXckefdVlV H/fbY06v3qVId50N7wDsT580xP5J5WzQ7S8elp+wh22l0WF+ETZED2mVFkYV1gygFAMO 3BoVF+/z/nJ7FvhItZb3Eq+LHjtVExnqCgYeqjzjfmv9lCqm4ye6IVVWxcRB+v4TKhas 7CcpF758BwMuh9ImMaeMxWBXZrqvJGMW55fbCto4kHJjSuNHj5UcuTt43TigPZ7NGXrV aMEx/2YYe+FHXM0PzD2TcC3hOGQZUx3eUE3qmMjmysK6TcQH3SWQLRvI44je6hHM/0LB eJ8Q== 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:cc: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=c/7l8yWIlYmMwz+LdcKhsBHxlHiAA1PZlKFTvo8miXU=; b=aewH2tOx03Pf/LBiSAxgUcaQt/CR8S6hnJSGz+Y7dHgtei1W9tqvvqoKs30oyO/J3y oETY+K1D6qfh1q1bGk9jtQLGzgWXimTIGerreY8l2Wy2ITd7kvqReO025jmVpQ3pX5PU 07LVbxtMwuvFZRjNWEL/7Iq0HXBVznL8SECznCekYP5FCHT5IsF+JQLqDaOvP6YNDQEt ZdQC94chwYJ6K8VuoyESbzskdGaixgFC60eN+RIBMp7bCBsNrmvTJP+EwMU21DEWlZ61 GZ65YPMrB8RCwdOpaAwJzZ1PDpiHz/N/9hhOO0qleUQdPht8HRb0SmFrOFRvgVacj8+g RQdA== X-Gm-Message-State: AMCzsaV7MXmtmCUSL97Ryd28qMOcWJYJpHk+gyx6PGh1JeK9CS28AUuo P3vaF+gik357crpRsmK2svKRnA== X-Google-Smtp-Source: AOwi7QBiCNzKDm1k/0gI4IL1y/KEBncEKwfXDtstWuIUSCy+QMml99ZD49Q9cqH7eZ42YKRf8Gmwgw== X-Received: by 10.31.140.14 with SMTP id o14mr2277595vkd.102.1507987665687; Sat, 14 Oct 2017 06:27:45 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.176.91.4 with SMTP id u4ls2437911uae.4.gmail; Sat, 14 Oct 2017 06:27:44 -0700 (PDT) X-Received: by 10.31.96.146 with SMTP id u140mr289292vkb.2.1507987664612; Sat, 14 Oct 2017 06:27:44 -0700 (PDT) In-Reply-To: <0cc942cf-a217-4175-98b0-b466ac224dc7@isocpp.org> X-Original-Sender: euloanty@live.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:34895 Archived-At: ------=_Part_2293_1746173585.1507987664129 Content-Type: multipart/alternative; boundary="----=_Part_2294_1515811434.1507987664130" ------=_Part_2294_1515811434.1507987664130 Content-Type: text/plain; charset="UTF-8" https://github.com/euloanty/cqwrteur-vector/blob/master/deque.cc Try this code. BTW. deque is "slower" than vector because of this dumb check if On Saturday, October 14, 2017 at 9:24:37 AM UTC-4, eulo...@live.com wrote: > O2 wont eliminate this cost. It is not optimization issue. I always use > -O2 to compile my programs > > On Saturday, October 14, 2017 at 9:18:56 AM UTC-4, Todd Fleming wrote: >> >> On Saturday, October 14, 2017 at 8:45:29 AM UTC-4, ejsvifq mabmip wrote: >>> >>> On Saturday, October 14, 2017 at 4:53:10 AM UTC-4, Magnus Fromreide >>> wrote: >>>> >>>> On Fri, Oct 13, 2017 at 07:38:20PM -0700, eulo...@live.com wrote: >>>> > Contiguous Containers: >>>> > >>>> > vector: >>>> > add non check push_back. non check resize etc. >>>> >>>> What does this mean, you are a bit thin on details here. >>>> >>>> ok. when you push_back an element into the vector, it will first check >>> whether size()==capacity(). It is an overhead when you know what exactly >>> the size of elements you need. >>> >>> For example: >>> >>> vector v; >>> v.reserve(10000000); >>> for(std::size_t i(0);I!=v.capacity();++i) >>> v.emplace_back(i); >>> >>> will be slower than >>> >>> vector v; >>> v.reserve(10000000); >>> for(std::size_t i(0);I!=v.capacity();++i) >>> v.nonchecked_emplace_back(i); >>> >> >> Benchmark requested using -O2 or higher; I doubt your performance claim. >> >> Todd >> >> -- 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/b50be367-9a0c-4d62-a392-d2b4471d7403%40isocpp.org. ------=_Part_2294_1515811434.1507987664130 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
https://github.com/euloanty/cqwrteur-vector/blob/mast= er/deque.cc

Try this code.

BTW. deque is "slower" than vector because of this dumb check i= f

On Saturday, October 14, 2017 at 9:24:37 AM UTC-4, eulo...@live.co= m wrote:
O2 wont eliminate this cost. It is not optimization issue. I always use -O= 2 to compile my programs

On Saturday, October 14, 2017 at 9:18:56 AM= UTC-4, Todd Fleming wrote:
On Saturday, October 14, 2017 at 8:45:29 AM UTC-4, ejsvifq mabmip = wrote:
On Saturday,= October 14, 2017 at 4:53:10 AM UTC-4, Magnus Fromreide wrote:
On Fri, Oct 13, 2017 at 07:38:20PM -0700, eulo...@live.com wrote:
> Contiguous Containers:
>=20
> vector:
> add non check push_back. non check resize etc.

What does this mean, you are a bit thin on details here.

ok. when you push_back an element into the vector, it= will first check whether size()=3D=3Dcapacity(). It is an overhead when yo= u know what exactly the size of elements you need.

For example:

vector<std::size_t> v;
v.reserve(10000000);
for(std::size_t i(0);I!=3Dv.capacity(= );++i)
=C2=A0 =C2=A0=C2=A0 v.emplace_back(i);

will be slower than

vector<std::size= _t> v;
v.reserve(10000000);
for(std::= size_t i(0);I!=3Dv.capacity();++i)
=C2=A0 =C2=A0=C2=A0 v.noncheck= ed_emplace_back(i);

Bench= mark requested using -O2 or higher; I doubt your performance claim.

Todd

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