220 7158 article Path: news.gmane.org!not-for-mail From: Philipp Stephani Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: "count_while" and "count_until" algorithms Date: Tue, 8 Oct 2013 22:16:30 +0200 Lines: 273 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=001a11c37ababadd5f04e840718e X-Trace: ger.gmane.org 1381263389 19206 80.91.229.3 (8 Oct 2013 20:16:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 8 Oct 2013 20:16:29 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBD35NAXJW4GBBH6Q2GJAKGQE5L7OBWA@isocpp.org Tue Oct 08 22:16:33 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ea0-f198.google.com ([209.85.215.198]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VTdho-0002NH-B1 for gclcip-std-proposals@m.gmane.org; Tue, 08 Oct 2013 22:16:32 +0200 Original-Received: by mail-ea0-f198.google.com with SMTP id z15sf11874528ead.1 for ; Tue, 08 Oct 2013 13:16:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=mime-version:in-reply-to:references:date:message-id:subject:from: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=19kZIqtEpQbdmoiPZz46g6HZ1ml+mEk9A4vtgL9k9HE=; b=X0XjWWY36Cs3e2wGElcooBZwnWaky5wy0cVb0ojWN1xBJr0J9pvqT1hvsYa002RK8K dp83UqfrrqihrCJ/egSov1R2CYxXAiqgZ5qT3kDby8bs1xHVkb5ExKhBQbIKYPhTGfcq g2AIBY5kYBZnNXEQqcnh2DJWODZ18sRq9WB271BKO96WZh47oyU+0d86fuxM7KALJO75 j4e24BdXMu3nSW4MBU30ixL+Ckx2bwcfVOcCRgVcIannpTCuQd08w1pugd0C55nKloCp C0atiFScp8E2Gd/QWLiv3Dn3+oljojcd13eQ16gi1nKh9XCrC1s6TEUKRE9aYIF2mmQX ++1A== X-Received: by 10.180.21.137 with SMTP id v9mr11714864wie.7.1381263391721; Tue, 08 Oct 2013 13:16:31 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.107.74 with SMTP id ha10ls1311528wib.42.canary; Tue, 08 Oct 2013 13:16:31 -0700 (PDT) X-Received: by 10.205.14.69 with SMTP id pp5mr3403512bkb.14.1381263390916; Tue, 08 Oct 2013 13:16:30 -0700 (PDT) Original-Received: from mail-la0-x229.google.com (mail-la0-x229.google.com [2a00:1450:4010:c03::229]) by mx.google.com with ESMTPS id ub7si5501073bkb.115.1969.12.31.16.00.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 08 Oct 2013 13:16:30 -0700 (PDT) Received-SPF: pass (google.com: domain of p.stephani2@gmail.com designates 2a00:1450:4010:c03::229 as permitted sender) client-ip=2a00:1450:4010:c03::229; Original-Received: by mail-la0-f41.google.com with SMTP id ec20so7564100lab.0 for ; Tue, 08 Oct 2013 13:16:30 -0700 (PDT) X-Received: by 10.112.14.102 with SMTP id o6mr3910799lbc.28.1381263390464; Tue, 08 Oct 2013 13:16:30 -0700 (PDT) Original-Received: by 10.112.213.73 with HTTP; Tue, 8 Oct 2013 13:16:30 -0700 (PDT) In-Reply-To: X-Original-Sender: p.stephani2@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of p.stephani2@gmail.com designates 2a00:1450:4010:c03::229 as permitted sender) smtp.mail=p.stephani2@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:7158 Archived-At: --001a11c37ababadd5f04e840718e Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I like the idea, they are simple and solve a generic problem that otherwise requires a for loop (unless you have at least a forward iterator, then you can use count_if + distance). 2013/10/8 R=E9my Lefevre > Hi, > > I thought about two new algorithms, that could be named "count_while" and > "count_until". Here are their behavior: > > template > > > typename iterator_traits::difference_type > > > count_while (InputIterator first, InputIterator last, UnaryPredicate = pred) > > { > typename iterator_traits::difference_type ret =3D 0; > > > while (first!=3Dlast && pred(*first)) { > > > ++ret; > ++first; > > > } > return ret; > > } > > > template > > > typename iterator_traits::difference_type > > > count_until (InputIterator first, InputIterator last, UnaryPredicate = pred) > > { > > typename iterator_traits::difference_type ret =3D 0; > > > while (first!=3Dlast && !pred(*first)) { > > > ++ret; > ++first; > > > } > return ret; > > > } > > > What do you think about adding these two components to the algorithms > library ? > > -- > > --- > 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/. > --=20 ---=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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposa= ls/. --001a11c37ababadd5f04e840718e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I like the idea, they are simple and solve a generic probl= em that otherwise requires a for loop (unless you have at least a forward i= terator, then you can use count_if + distance).


2013/10/8 R=E9my Lefevre <lefevrere= my@gmail.com>
Hi,

I thought about two new algorithms, that could = be named "count_while" and "count_until". Here are thei= r behavior:

template <class InputIterator, class UnaryPredicate&=
gt;



=A0 typename iterator_traits<InputIterator>::difference_type



=A0 =A0 count_while (InputIterator first, InputIterator last, UnaryP=
redicate pred)



{
=A0 typename iterator_traits<InputIterator>::difference_type ret =3D 0;



=A0 while (firs=
t!=3Dlast && pred(*f=
irst)) {



=A0 =A0 ++re=
t;
=A0 =
=A0 ++first<=
/span>;



=A0 }
=A0=
 return ret;

}

template <class InputIterator, class UnaryPredicate&=
gt;



=A0 typename iterator_traits<InputIterator>::difference_type



=A0 =A0 count_until (InputIterator first, InputIterator last, UnaryP=
redicate pred)



{
<=
pre>=A0 ty=
pename iterator_traits<InputIterat=
or>::diff=
erence_type ret =3D 0;



=A0 while (firs=
t!=3Dlast && !pred(*=
first)) {



=A0 =A0 ++re=
t;
=A0 =
=A0 ++first<=
/span>;



=A0 }
=A0=
 return ret;


}

What do you think about adding these two components to the algorithms l= ibrary ?

--
=A0
---
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--
 
---
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-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/<= /a>.
--001a11c37ababadd5f04e840718e-- .