220 40818 <988bb886-95a1-4484-9461-824368477145@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: mutant.sheepdog@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Pointer to pointer representation Date: Mon, 29 Oct 2018 14:46:08 -0700 (PDT) Lines: 117 Approved: news@gmane.org Message-ID: <988bb886-95a1-4484-9461-824368477145@isocpp.org> References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_1957_270047720.1540849569036" X-Trace: blaine.gmane.org 1540849446 27470 195.159.176.226 (29 Oct 2018 21:44:06 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 29 Oct 2018 21:44:06 +0000 (UTC) Cc: tecoberg@gmail.com To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDV57NMMVALBBIX73XPAKGQEIDR6QUI@isocpp.org Mon Oct 29 22:44:02 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yb1-f199.google.com ([209.85.219.199]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gHFKL-000729-JC for gclcip-std-proposals@m.gmane.org; Mon, 29 Oct 2018 22:44:01 +0100 Original-Received: by mail-yb1-f199.google.com with SMTP id z1-v6sf7440565ybf.4 for ; Mon, 29 Oct 2018 14:46:12 -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=ODh8WU20Tuf1wp6brC3fRKuJ7UTavSSkFwOyde7Kfrg=; b=bN2M8quGnE1Q8kfcMG4tDJKYaYh2+5G1nd0iFoXrNBu7p+3Sg7wnjpm3ZXoAFjhF13 8u7ToMlsAmsRrM5c7+GDRgaFrthdkJRwD08+0jOs0gJ8eQUaLKET7BkKJ+4p3bMbrI5Y F5HLgl55abVfaBg9kwS8d+88hMcRVDFLx5HWwp/p6v2cUcudbiH9RFz2+oIqczWE+rdB IchXcmqAfL0A4B74UC12mcH9/ZzOnlIvCGbMJVFAsK0PPCI5hvy5+U7QOahlfih5E8Bg V0t/KyZenY9Ok20DHKuqPulJNmy78CFQrfkA3fl/AcYAEr96VOaW34xYmSFGwnJqRE1N rMiA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; 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=ODh8WU20Tuf1wp6brC3fRKuJ7UTavSSkFwOyde7Kfrg=; b=NIyJiQ0FW85zaPp1NOkMS5DwGuo/YK3LuEc7NxweLBLmiHqjIt+28DBTSg2/VZeAKQ dkbZnObcFR0e7q1JCoIXwF/me8/aaga9dwOcDTYbsOH2k4IL2ZzKnIgi7Eh9Ka3SePZL VCySLMgz0QlEYcMjl10aSHlJjvULHjOiZ4S6wMb497n+tKJfCNuR8jzSfq6vz/jEnDZZ Tb5o5doVdpIAaxDwY2ndwk1ZeDKaYM6YGA9HUZL4fqMf+9vYXqUOPfJRzKbJC6t4AGgq FmNmOtihY88dfd3kX2Me0i0hF/e7p5erB29PzhIHU/G47hWVoybIbFIRBPTjju71ui5b ciRw== 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=ODh8WU20Tuf1wp6brC3fRKuJ7UTavSSkFwOyde7Kfrg=; b=uPkGKqkPJ5yn9zYFcxaYHrNWXX8qHrFGoBg+gmP1h6dGOHJn8xafepPXQ44b+PZIZ7 /f21oxUIwG7bRyQwve49+U5225MZDivaiTPQXFGZQ/YMTb5wd0VpEBlHEZYKqx2MT0A2 4AdIXyzwCxmvJyJL9DVn1BbmXD2v3YXJ/orPFZjZTN6CMN2xXNM+q/xLioqvYW2vcSgc 5+qnupMimbxncudrzrcpfDiLSHnEFzGYVa2sqQRYbIcewmJH5XGtqK8RbIsZtRvVzsD6 9gu7x07fcm2EhCye3+EOTsekpMfgvXjKILOcYoQptv1ZgV6nV0QgzJfQOhlBxy3mQ8le 1FRg== X-Gm-Message-State: AGRZ1gI4venHgefpHPQ3zRFE9KxwJ2yCvEq6hDzMPk/sPh8SB2/j26vV ERBGTKE+JxdhOHsXzAiRrlKtwA== X-Google-Smtp-Source: AJdET5dvu7cV+oADgcdYgKlWs1RQv2tkAL2PmaLqjoeVjgXbnhvQzIpb6pGDrhJWVC4M0uMmj0GKyw== X-Received: by 2002:a81:ae18:: with SMTP id m24-v6mr94462ywh.15.1540849571788; Mon, 29 Oct 2018 14:46:11 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a81:3d45:: with SMTP id k66-v6ls5754031ywa.11.gmail; Mon, 29 Oct 2018 14:46:10 -0700 (PDT) X-Received: by 2002:a0d:d703:: with SMTP id z3-v6mr665ywd.7.1540849569947; Mon, 29 Oct 2018 14:46:09 -0700 (PDT) In-Reply-To: X-Original-Sender: Mutant.Sheepdog@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org 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:40818 Archived-At: ------=_Part_1957_270047720.1540849569036 Content-Type: multipart/alternative; boundary="----=_Part_1958_886195860.1540849569036" ------=_Part_1958_886195860.1540849569036 Content-Type: text/plain; charset="UTF-8" I don't think pointer-pointers are common enough to warrant adding their own operator to the language when (*ptp)->FuncMember() and **ptp.FuncMember() already work well enough. I can think of 2 main situations where I've run into pointer pointers. The first is functions that return a handle via an out param (which could be replaced with an optional return val) and in those cases you wouldn't typically be dereferencing the pointer-pointer in the body of the function, and the calling function would probably only have a regular pointer (passing the address of the pointer into the function). The second case is iterators to pointers and in those cases it would often better to use (*ptp)-> anyway so that the iterator type could change without the dereference having to change. I feel that pointer-pointers should be rare, and shouldn't get special syntax when existing syntax works. On Monday, 29 October 2018 18:00:15 UTC+11, teco...@gmail.com wrote: > > Hi, > > If we have a container of unitque_ptr/shared_ptr objects, to reference to > them we can usethe follow notations: > > *p->FuncMember();* //Same as *(*p).FuncMember();* > > but, some times I need to create a pointer to this pointer and I use to > write the follow notation: > > *(*p2p)->FuncMember();* > > I think it will be a good idea if c++ could have a notation to this > situations like: > > *p2p=>FuncMember() *//or > > *p2p+>FuncMember()* //or > > *p2p#>FuncMember()* //or > > *p2p:>FuncMember()* > > What do you think? > > I hope I helped in some way. > > > -- 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/988bb886-95a1-4484-9461-824368477145%40isocpp.org. ------=_Part_1958_886195860.1540849569036 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I don't think pointer-pointers are common enough = to warrant adding their own operator to the language when (*ptp)->FuncMe= mber() and **ptp.FuncMember() already work well enough.

I can think of 2 main situations where I've run into pointer poin= ters.
The first is functions that return a handle via an out param (whic= h could be replaced with an optional return val) and in those cases you wou= ldn't typically be dereferencing the pointer-pointer in the body of the= function, and the calling function would probably only have a regular poin= ter (passing the address of the pointer into the function).
The s= econd case is iterators to pointers and in those cases it would often bette= r to use (*ptp)-> anyway so that the iterator type could change without = the dereference having to change.

I feel that = pointer-pointers should be rare, and shouldn't get special syntax when = existing syntax works.


On Monday, 29 October 2018 1= 8:00:15 UTC+11, teco...@gmail.com wrote:
Hi,=C2=A0

If we h= ave a container of unitque_ptr/shared_ptr objects, to reference to them we = can usethe follow notations:

p->FuncMember()= ;=C2=A0=C2=A0 //Same as (*p).FuncMember();

<= div>but, some times I need to create a pointer to this pointer and I use to= write the follow notation:

(*p2p)->FuncMemb= er();

I think it will be a good idea if c++ co= uld have a notation to this situations like:

p2= p=3D>FuncMember() //or

p2p+>FuncMembe= r() //or

p2p#>FuncMember() //or

p2p:>FuncMember()

What do you think?

I hope I helped in some way.=


--
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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/988bb886-95a1-4484-9461-824368477145= %40isocpp.org.
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