220 7462 article Path: news.gmane.org!not-for-mail From: "Billy O'Neal" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: To add the method append for all sequential containers that have method push_back Date: Wed, 23 Oct 2013 17:10:55 -0700 Lines: 478 Approved: news@gmane.org Message-ID: References: <4167b82e-a3cc-44ce-9825-b52514bc1531@isocpp.org> <357325b0-cec5-4d22-ad56-9bb66f76b458@isocpp.org> <983ff074-5d8c-488a-b06c-49d53d5b7a5b@isocpp.org> <369298d9-3f8b-405a-8bfe-ae209372a26f@isocpp.org> <5266DEEC.7090805@gmail.com> <7c9a2637-65d8-4d54-bd3c-b46c0c22b34f@isocpp.org> <70a718dd-eca7-4845-8e9c-0313581ed453@isocpp.org> <6b9f62b2-21b1-4c62-a815-217d77a59a23@isocpp.org> <0e98fae6-2dc5-4e50-8659-5334012c4dd4@isocpp.org> <0d945506-2a09-4645-a68e-ada2b9898aa9@isocpp.org> <69dd52d3-c35e-4391-b998-d1a35c4599d6@isocpp.org> <0001b7d6-42ab-4f47-8104-1c5e93ecfbc4@isocpp.org> <03ecdc90-1973-4e34-82c9-ab0043241a2b@isocpp.org> <94c6cdf1-e640-4cc9-9c4b-e2605610a715@isocpp.org> <8e3f0b94-b0a3-43e2-9a2c-853734b9d6c3@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=089e0160c2440d4cc704e9717a7d X-Trace: ger.gmane.org 1382573494 18441 80.91.229.3 (24 Oct 2013 00:11:34 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 24 Oct 2013 00:11:34 +0000 (UTC) To: std-proposals Original-X-From: std-proposals+bncBDKLBLVE6ADBBN6LUGJQKGQETVCAGOY@isocpp.org Thu Oct 24 02:11:40 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pa0-f71.google.com ([209.85.220.71]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VZ8WX-0003qZ-Co for gclcip-std-proposals@m.gmane.org; Thu, 24 Oct 2013 02:11:37 +0200 Original-Received: by mail-pa0-f71.google.com with SMTP id kx10sf3235983pab.2 for ; Wed, 23 Oct 2013 17:11:36 -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: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=dY/146MwrV7f+E/SC5skNqDKzUjpKdVPvCS1b+7rwWI=; b=jReV9GyScQRKCzRglCo015MAYDMdTtURX7N0GG75MxJMJGuSEbG3RZoAHRbgCsi7dJ bi6DgHlCSRUund6dfWRrUv++4hfrOlrj+4zj1X/Ej90/VyTzun6W5BhlXHG/jxgG/0Tr 3fI0IIMru6oOAGkf92PTC8DRtxNY52jwiFA1acP8oOPOfm/kCgSfx1XpmKCYpSVBbxv5 mJIjwm1i/+VeTzMY0LWjmDIwrZJtg1V/mjCj5mp3N1sTRsRViEgQQhtBj+Irvb7RvhOf Psh3aYjfU8JpGUNa22R7DATyuZ7xyBm9xoeWuWl1X/shvju0vAVkQYlPCFZ+GwtLwaSD t8hQ== X-Received: by 10.66.149.67 with SMTP id ty3mr154599pab.27.1382573496072; Wed, 23 Oct 2013 17:11:36 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.182.117.197 with SMTP id kg5ls410153obb.61.gmail; Wed, 23 Oct 2013 17:11:35 -0700 (PDT) X-Received: by 10.182.98.162 with SMTP id ej2mr4195274obb.61.1382573495467; Wed, 23 Oct 2013 17:11:35 -0700 (PDT) Original-Received: from mail-ob0-x22e.google.com (mail-ob0-x22e.google.com [2607:f8b0:4003:c01::22e]) by mx.google.com with ESMTPS id fm3si6406510oeb.100.2013.10.23.17.11.35 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 23 Oct 2013 17:11:35 -0700 (PDT) Received-SPF: pass (google.com: domain of billy.oneal@gmail.com designates 2607:f8b0:4003:c01::22e as permitted sender) client-ip=2607:f8b0:4003:c01::22e; Original-Received: by mail-ob0-f174.google.com with SMTP id vb8so1626983obc.33 for ; Wed, 23 Oct 2013 17:11:35 -0700 (PDT) X-Received: by 10.60.165.5 with SMTP id yu5mr45148oeb.105.1382573495108; Wed, 23 Oct 2013 17:11:35 -0700 (PDT) Original-Received: by 10.182.87.37 with HTTP; Wed, 23 Oct 2013 17:10:55 -0700 (PDT) In-Reply-To: <8e3f0b94-b0a3-43e2-9a2c-853734b9d6c3@isocpp.org> X-Original-Sender: billy.oneal@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of billy.oneal@gmail.com designates 2607:f8b0:4003:c01::22e as permitted sender) smtp.mail=billy.oneal@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:7462 Archived-At: --089e0160c2440d4cc704e9717a7d Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: quoted-printable >It is not clear what is the return type of append. By that standard, the return type of append here isn't clear either: v2.append( std::next( range.second ), v1.end() ); Member-ness or nonmember-ness doesn't tell the caller *anything* about the return type. >can confuse users because they will think that they can use any container because the function iis a general non-member function By that metric, any STL algorithm that requires bidirectional iterators wouldn't be allowed, because they don't work with input iterators. In fact, advance would be a great *counter example* to your claim, because it isn't obvious why std::advance(std::istream_iterator( ... ), -2) wouldn't work. Users are expected to understand the function they are calling before calling it. Billy O'Neal https://github.com/BillyONeal/ http://stackoverflow.com/users/82320/billy-oneal Malware Response Instructor - BleepingComputer.com On Wed, Oct 23, 2013 at 4:59 PM, Vlad from Moscow wrot= e: > They will think so by analogy with other similar general functions as for > example advance that can be used with any type of iterators (except outpu= t > iterators). > > =DE=C5=D4=D7=C5=D2=C7, 24 =CF=CB=D4=D1=C2=D2=D1 2013 =C7., 3:57:48 UTC+4 = =D0=CF=CC=D8=DA=CF=D7=C1=D4=C5=CC=D8 Vlad from Moscow > =CE=C1=D0=C9=D3=C1=CC: > >> In my personal opinion there is two problems. It is not clear what is th= e >> return type of append. And such record can confuse users because they wi= ll >> think that they can use any container because the function iis a general >> non-member function. >> >> =DE=C5=D4=D7=C5=D2=C7, 24 =CF=CB=D4=D1=C2=D2=D1 2013 =C7., 3:51:46 UTC+4= =D0=CF=CC=D8=DA=CF=D7=C1=D4=C5=CC=D8 Billy O'Neal >> =CE=C1=D0=C9=D3=C1=CC: >> >>> And yet, is no less clearly expressed as: >>> std::vector v2( v1.begin(), range.first ); >>> append( v2, std::next( range.second ), v1.end() ); >>> >>> which you can already do today without needing a standard modification. >>> >>> Billy O'Neal >>> https://github.com/BillyONeal/ >>> http://stackoverflow.com/**users/82320/billy-oneal >>> Malware Response Instructor - BleepingComputer.com >>> >>> >>> On Wed, Oct 23, 2013 at 4:32 PM, Vlad from Moscow wro= te: >>> >>>> Billy, I do not think that append flows out of operator +=3D. It looks >>>> like that operator +=3D flows out of append.:) >>>> >>>> To demonstrate that append looks much better than insert I will show >>>> the following assignment. >>>> Let;s assume that there is a vector v1 and you need to copy its >>>> elements in another vector v2 excluding some range that specified by a= pair >>>> of iterators. For example one iterator points the first negative value= of >>>> the vector and the second iterator points the last negative value of t= he >>>> vector. The simplest way to do the assignment is to write >>>> >>>> std::vector v2( v1.begin(), range.first ); >>>> v2.append( std::next( range.second ), v1.end() ); >>>> >>>> That is at first the part of the original vector before the first >>>> iterator was copied and then the tail of the original vector was >>>> appended.. The code looks very logically and clearly due to using of a= ppend. >>>> >>>> >>>> >>>> >>>> =DE=C5=D4=D7=C5=D2=C7, 24 =CF=CB=D4=D1=C2=D2=D1 2013 =C7., 3:07:04 UTC= +4 =D0=CF=CC=D8=DA=CF=D7=C1=D4=C5=CC=D8 Billy O'Neal >>>> =CE=C1=D0=C9=D3=C1=CC: >>>> >>>>> Again, append makes sense for basic_string because it corresponds to >>>>> basic_string's operator+=3D. That operation doesn't necessarily make = sense >>>>> for all containers. >>>>> >>>>> Billy O'Neal >>>>> https://github.com/BillyONeal/ >>>>> http://stackoverflow.com/**users**/82320/billy-oneal >>>>> Malware Response Instructor - BleepingComputer.com >>>>> >>>>> >>>>> On Wed, Oct 23, 2013 at 4:05 PM, Vlad from Moscow w= rote: >>>>> >>>>>> In fact there is nothing new with the method append because it >>>>>> already exists for std::basic_string. If somebody has some doubts th= en I >>>>>> advise to try do not use append with std::basic string and substitut= e it >>>>>> everywhere in code for insert. I am sure that through a month of suc= h >>>>>> coding he will quickly understand that method append is necessary. >>>>>> >>>>>> Introducing method append just makes the common interface of >>>>>> sequential containers more consistent. >>>>>> >>>>>> =DE=C5=D4=D7=C5=D2=C7, 24 =CF=CB=D4=D1=C2=D2=D1 2013 =C7., 2:52:13 U= TC+4 =D0=CF=CC=D8=DA=CF=D7=C1=D4=C5=CC=D8 Zhihao Yuan >>>>>> =CE=C1=D0=C9=D3=C1=CC: >>>>>> >>>>>>> On Oct 23, 2013 6:31 PM, "Zhihao Yuan" wrote: >>>>>>> > I think we'd better not to regard this as merely a syntax sugar. >>>>>>> I looked at libc++ code and I found that since the position is know= n to be >>>>>>> end(), append() can be implemented in a much simpler way compared w= ith >>>>>>> insert(). Not sure how beneficial it is though, but so far it look= s not >>>>>>> too useless. >>>>>>> >>>>>>> PS: If you agree with this rationale, I would suggest to add >>>>>>> prepend() method to deque, list, and forward_list as well. >>>>>>> >>>>>> -- >>>>>> >>>>>> --- >>>>>> 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-proposal...@**isocpp.org. >>>>>> To post to this group, send email to std-pr...@isocpp.org. >>>>>> >>>>>> Visit this group at http://groups.google.com/a/**iso** >>>>>> cpp.org/group/std-**proposals/ >>>>>> . >>>>>> >>>>> >>>>> -- >>>> >>>> --- >>>> 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-proposal...@isocpp.org. >>>> To post to this group, send email to std-pr...@isocpp.org. >>>> Visit this group at http://groups.google.com/a/**isocpp.org/group/std-= * >>>> *proposals/ >>>> . >>>> >>> >>> -- > > --- > 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/. --089e0160c2440d4cc704e9717a7d Content-Type: text/html; charset=KOI8-R Content-Transfer-Encoding: quoted-printable
>It is not clear what is the return type of append.
By = that standard, the return type of append here isn't clear either:
=
v2.append( std:= :next(=9Arange.second ), v1.end()=9A);

Member-ness or nonmember-ness doesn't tell the= caller *anything* about the return type.

>can confuse users because they will think that they can use a= ny container because the function iis a general non-member function<= /div>

By = that metric, any STL algorithm that requires bidirectional iterators wouldn= 't be allowed, because they don't work with input iterators. In fac= t, advance would be a great *counter example* to your claim, because it isn= 't obvious why std::advance(std::istream_iterator( ... ), -2) wouldn= 9;t work.

Use= rs are expected to understand the function they are calling before calling = it.

Bil= ly O'Neal
Malware Response Instructor - BleepingComputer.com


On Wed, Oct 23, 2013 at 4:59 PM, Vlad fr= om Moscow <vlad.moscow@mail.ru> wrote:
They will think so by analogy with other similar gene= ral functions as for example advance that can be used with any type of iter= ators (except output iterators).

=DE=C5=D4=D7=C5=D2=C7, 24 = =CF=CB=D4=D1=C2=D2=D1 2013=9A=C7., 3:57:48 UTC+4 =D0=CF=CC=D8=DA=CF=D7=C1= =D4=C5=CC=D8 Vlad from Moscow =CE=C1=D0=C9=D3=C1=CC:
In my personal opinion the= re is two problems. It is not clear what is the return type of append. And = such record can confuse users because they will think that they can use any= container because the function iis a general non-member function.

=DE=C5=D4=D7=C5=D2=C7, 24 =CF=CB=D4=D1=C2=D2=D1 2013=9A=C7., 3:51:= 46 UTC+4 =D0=CF=CC=D8=DA=CF=D7=C1=D4=C5=CC=D8 Billy O'Neal =CE=C1=D0=C9= =D3=C1=CC:
And yet, is no less clearly expressed as:
std::vector<int> v2(= v1.begin(),=9Arange.first );
append( v2, std::next(=9Arange.second ), v1.end()=9A);

which you can already do today = without needing a standard modification.

Billy O'Neal
Malware Response Instructor - BleepingComputer.com


On Wed, Oct 23, 2013 at 4:32 PM, Vlad fr= om Moscow <vlad....@mail.ru> wrote:
Billy, I do not think that append flows out of operat= or +=3D. It looks like that operator +=3D flows out of append.:)
= =9A
To demonstrate that append looks much better than insert I wi= ll show the following assignment.
=9ALet;s assume that there is a vector v1 and you need to copy=9A its = elements in another vector v2 excluding some range that specified by a=9Apa= ir of=9Aiterators. For example one iterator points=9Athe first negative val= ue of the vector and the=9Asecond iterator points the last negative value o= f the vector. The simplest way to do the assignment is to write
=9A
std::vector<int> v2( v1.begin(),=9Arange.first );<= /div>
v2.append( std::next(=9Arange.second ), v1.end()=9A);
= =9A
That is at first the part of the original vector before the f= irst iterator was copied and then=9Athe tail of the original vector =9Awas = appended.. The code looks very logically and clearly due to using of append= ..
=9A
=9A
=9A

=DE=C5=D4=D7=C5=D2=C7, 2= 4 =CF=CB=D4=D1=C2=D2=D1 2013=9A=C7., 3:07:04 UTC+4 =D0=CF=CC=D8=DA=CF=D7=C1= =D4=C5=CC=D8 Billy O'Neal =CE=C1=D0=C9=D3=C1=CC:
Again, append makes sense for basic_string because it= corresponds to basic_string's operator+=3D. That operation doesn't= necessarily make sense for all containers.

Billy O'Neal
Malware Response Instructor - BleepingComputer.com


On Wed, Oct 23, 2013 at 4:05 = PM, Vlad from Moscow <vlad....@mail.ru> wrote:
In fact there is nothing new with the method append b= ecause it already exists for std::basic_string.=9AIf somebody has some doub= ts then I advise to try do not use append with std::basic string and substi= tute it everywhere in code for insert. I am sure that through a month of su= ch coding=9Ahe will quickly understand that method append is necessary.
=9A
Introducing method append=9Ajust makes=9Athe common inte= rface of sequential containers more consistent.

=DE=C5=D4=D7= =C5=D2=C7, 24 =CF=CB=D4=D1=C2=D2=D1 2013=9A=C7., 2:52:13 UTC+4 =D0=CF=CC=D8= =DA=CF=D7=C1=D4=C5=CC=D8 Zhihao Yuan =CE=C1=D0=C9=D3=C1=CC:

On Oct 23, 2013 6:31 PM, "Zhihao Yuan" <z...@miator.net<= /a>> wrote:
> I think we'd better not to regard this as merely a syntax sugar.= =9A I looked at libc++ code and I found that since the position is known to= be end(), append() can be implemented in a much simpler way compared with = insert().=9A Not sure how beneficial it is though, but so far it looks not = too useless.

PS: If you agree with this rationale, I would suggest to add prepend() m= ethod to deque, list, and forward_list as well.

--
=9A
---
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-proposal...@isocpp.org.
To post to this group, send email to std-pr...@isocpp.org.

--
=9A
---
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-proposal...@isocpp.org.
To post to this group, send email to std-pr...@isocpp.org.
Visit this group at http://groups.google.com/a/isocpp.= org/group/std-proposals/.

--
=9A
---
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/gro= up/std-proposals/.

--
 
---
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>.
--089e0160c2440d4cc704e9717a7d-- .