220 7171 article Path: news.gmane.org!not-for-mail From: Vlad from Moscow Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: "count_while" and "count_until" algorithms Date: Tue, 8 Oct 2013 13:37:13 -0700 (PDT) Lines: 341 Approved: news@gmane.org Message-ID: References: <285a478e-ce03-42b9-9196-c7d0855e11aa@isocpp.org> <82850309-b16b-44bd-b478-e2e63e43d6ca@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_501_26566878.1381264633462" X-Trace: ger.gmane.org 1381264638 1485 80.91.229.3 (8 Oct 2013 20:37:18 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 8 Oct 2013 20:37:18 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCXLLRHD7IDRB66Z2GJAKGQEDU4SB4A@isocpp.org Tue Oct 08 22:37:19 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oa0-f70.google.com ([209.85.219.70]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VTe1s-0005Z0-DR for gclcip-std-proposals@m.gmane.org; Tue, 08 Oct 2013 22:37:16 +0200 Original-Received: by mail-oa0-f70.google.com with SMTP id g12sf28816333oah.5 for ; Tue, 08 Oct 2013 13:37:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; 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=SWEG9TKufcsbqb17ZvFFK50AdGkzCr1StdEN1798/sA=; b=fKBFxTvfmUQbZBGJGnlwR9QQN5DX+VS+9E8xO2sdb89lkNGaui32sAumAAqakXYb44 HtAOa0QrvQJJZUpcekqqKxQKc6paqNKZ3Qpk+qb3zvsCiZyTgEMzADjiWFBU2m+ySqP1 M3TyoTXEnkxga27kWWi6FRCRu1AcCS9txEBgfmWciF8NMmfmu0H0FuVtrQFr42Ntp/08 rJuSgKbVt7dbWJKl41DlyPn4ZplayyIwAIRwKdre6iVrSOp6p4wPw7gGE2wCkhG7meIt JyYFRpBdarcQMD/Cijg9tSuULlfG1lBraudY/7txumUr6xif5KjJ6u9r4bQorGMkxb7q EafA== X-Received: by 10.50.129.42 with SMTP id nt10mr2285404igb.0.1381264635374; Tue, 08 Oct 2013 13:37:15 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.50.67.48 with SMTP id k16ls735067igt.40.gmail; Tue, 08 Oct 2013 13:37:14 -0700 (PDT) X-Received: by 10.50.25.98 with SMTP id b2mr1067015igg.3.1381264634922; Tue, 08 Oct 2013 13:37:14 -0700 (PDT) In-Reply-To: <82850309-b16b-44bd-b478-e2e63e43d6ca@isocpp.org> X-Original-Sender: vlad.moscow@mail.ru 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:7171 Archived-At: ------=_Part_501_26566878.1381264633462 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable So I would propose name count_first_if instead of the both suggested=20 algorithms count_until and count_while. =20 =D1=81=D1=80=D0=B5=D0=B4=D0=B0, 9 =D0=BE=D0=BA=D1=82=D1=8F=D0=B1=D1=80=D1= =8F 2013 =D0=B3., 0:35:01 UTC+4 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2= =D0=B0=D1=82=D0=B5=D0=BB=D1=8C Vlad from Moscow=20 =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB: > Or the following definition > =20 > [code] > template > T accumulate_first_if( InputIterator first,=20 > InputIterator last, > T init, > UnaryPredicate unary_predicate ) > { > for ( ; first !=3D last && unary_predicate( *first ) ; ++first ) > { > init =3D ( T )( init + *first ); > } > return ( init ); > } > [/code] > > =D1=81=D1=80=D0=B5=D0=B4=D0=B0, 9 =D0=BE=D0=BA=D1=82=D1=8F=D0=B1=D1=80=D1= =8F 2013 =D0=B3., 0:32:31 UTC+4 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2= =D0=B0=D1=82=D0=B5=D0=BB=D1=8C Vlad from Moscow=20 > =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB: > >> =20 >> [code] >> In some thread here I proposed the similar idea for algorithm=20 >> std::accumulate. >> template > BinaryOperation> >> T accumulate_first_if( InputIterator first,=20 >> InputIterator last, >> T init, >> UnaryPredicate unary_predicate, >> BinaryOperation binary_operation ) >> { >> for ( ; first !=3D last && unary_predicate( *first ) ; ++first ) >> { >> init =3D binary_operation( init, *first ); >> } >> return ( init ); >> } >> [/code] >> =D1=81=D1=80=D0=B5=D0=B4=D0=B0, 9 =D0=BE=D0=BA=D1=82=D1=8F=D0=B1=D1=80= =D1=8F 2013 =D0=B3., 0:04:23 UTC+4 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0= =B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C R=C3=A9my Lefevre =D0=BD=D0=B0=D0=BF=D0= =B8=D1=81=D0=B0=D0=BB: >> >>> Hi, >>> >>> I thought about two new algorithms, that could be named "count_while"= =20 >>> and "count_until". Here are their behavior: >>> >>> template >>> >>> >>> typename iterator_traits::difference_type >>> >>> >>> count_while (InputIterator first, InputIterator last, UnaryPredicat= e 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, UnaryPredicat= e 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= =20 >>> library ? >>> >> --=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/. ------=_Part_501_26566878.1381264633462 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
So I would propose name count_first_if instead of the= both suggested algorithms count_until and count_while.
 

=D1=81=D1=80=D0=B5=D0=B4=D0=B0, 9 =D0=BE=D0=BA=D1=82=D1=8F=D0= =B1=D1=80=D1=8F 2013 =D0=B3., 0:35:01 UTC+4 =D0=BF=D0=BE=D0=BB=D1=8C= =D0=B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C Vlad from Moscow =D0=BD=D0= =B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB:
Or the following definition
 
[cod= e]
template <class InputIterator, class T, class UnaryPredicat= e>
T accumulate_first_if( InputIterator first,
   =             &nb= sp;    InputIterator last,
     =    T init,
        UnaryPre= dicate unary_predicate )
{
 for ( ; first !=3D last && u= nary_predicate( *first ) ; ++first )
 {
  init =3D ( T= )( init + *first );
 }
 return ( init );
}
[/code]

=D1=81=D1=80=D0=B5=D0=B4=D0=B0, 9 =D0=BE=D0= =BA=D1=82=D1=8F=D0=B1=D1=80=D1=8F 2013 =D0=B3., 0:32:31 UTC+4 =D0=BF= =D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C Vlad fro= m Moscow =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB:
 
[code]
In some= thread here I proposed the similar idea for algorithm std::accumulate.
template <class InputIterator, class T, class UnaryPredicate, cla= ss BinaryOperation>
T accumulate_first_if( InputIterator first,
&= nbsp;           &nbs= p;       InputIterator last,
  &= nbsp;     T init,
     &nbs= p;  UnaryPredicate unary_predicate,
     &= nbsp;  BinaryOperation binary_operation )
{
 for ( ; first = !=3D last && unary_predicate( *first ) ; ++first )
 {
&n= bsp; init =3D binary_operation( init, *first );
 }
&= nbsp;return ( init );
}
[/code]
=D1=81=D1=80=D0=B5=D0= =B4=D0=B0, 9 =D0=BE=D0=BA=D1=82=D1=8F=D0=B1=D1=80=D1=8F 2013 =D0=B3., = 0:04:23 UTC+4 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5= =D0=BB=D1=8C R=C3=A9my Lefevre =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB:<= /div>
Hi,

I thought abo= ut two new algorithms, that could be named "count_while" and "count_until".= Here are their behavior:

template<=
/span> <class InputIterator, class UnaryP=
redicate>


  typename iterator_traits<InputIterator>::difference_type


    count_while (=
InputIterator first, InputIterator last, UnaryPredicate pred)


{
  typename iterator_tr=
aits<InputIterator>::diff=
erence_type ret =3D<=
span style=3D"color: rgb(0, 0, 0);"> 0;


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


    ++ret;
    ++first;


  }
  return ret;


}
= 

template<=
/span> <class InputIterator, class UnaryP=
redicate>


  typename iterator_traits<InputIterator>::difference_type


    count_until (=
InputIterator first, InputIterator last, UnaryPredicate pred)


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


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


    ++ret;
    ++first;


  }
  return ret;<=
br>

}

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

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