220 26557 <00caca39-d36a-475c-840f-79759e99265d@isocpp.org> article Path: news.gmane.org!not-for-mail From: xavinaar@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: auto type deduction for *_cast return argument Date: Tue, 5 Jul 2016 01:18:44 -0700 (PDT) Lines: 94 Approved: news@gmane.org Message-ID: <00caca39-d36a-475c-840f-79759e99265d@isocpp.org> References: <58140e46-2adc-4eac-8f51-72d3685cdf0b@isocpp.org> <7E3409C2-A2AC-4562-BB06-6D5D5ACE8AC8@gmail.com> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_103_462831137.1467706724557" X-Trace: ger.gmane.org 1467706729 28593 80.91.229.3 (5 Jul 2016 08:18:49 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 5 Jul 2016 08:18:49 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCX4LEEDVMDRBZO25W5QKGQEI3HRNHQ@isocpp.org Tue Jul 05 10:18:49 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qk0-f197.google.com ([209.85.220.197]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1bKLZ9-0006Tl-6O for gclcip-std-proposals@m.gmane.org; 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Tue, 05 Jul 2016 01:18:46 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.107.135.90 with SMTP id j87ls1696703iod.46.gmail; Tue, 05 Jul 2016 01:18:45 -0700 (PDT) X-Received: by 10.36.196.5 with SMTP id v5mr341685itf.4.1467706725483; Tue, 05 Jul 2016 01:18:45 -0700 (PDT) In-Reply-To: <7E3409C2-A2AC-4562-BB06-6D5D5ACE8AC8@gmail.com> X-Original-Sender: Xavinaar@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:26557 Archived-At: ------=_Part_103_462831137.1467706724557 Content-Type: multipart/alternative; boundary="----=_Part_104_1575461357.1467706724557" ------=_Part_104_1575461357.1467706724557 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On countrary: passing *dynamic_cast* to function always means you want to= =20 cast to function argument type. =D0=B2=D1=82=D0=BE=D1=80=D0=BD=D0=B8=D0=BA, 5 =D0=B8=D1=8E=D0=BB=D1=8F 2016= =D0=B3., 14:59:06 UTC+7 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2=D0=B0= =D1=82=D0=B5=D0=BB=D1=8C Jonathan Coe =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0= =D0=BB: > > Thanks for suggesting this, I'm afraid I don't think I like this idea. > > It saves a bit of typing but would make it less clear what's going on and= =20 > in cases where a function signature changes would change the meaning of= =20 > existing code without any edits being made > > f(A a); > > Changed to > > f(B b); > > Would change the meaning of=20 > > f(dynamic_cast(x)); > > In a rather non-obvious way. > > Regards > > Jon > > --=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. To view this discussion on the web visit https://groups.google.com/a/isocpp= ..org/d/msgid/std-proposals/00caca39-d36a-475c-840f-79759e99265d%40isocpp.or= g. ------=_Part_104_1575461357.1467706724557 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On countrary: passing dynamic_cast to function alwa= ys means you want to cast to function argument type.

=D0=B2=D1=82=D0= =BE=D1=80=D0=BD=D0=B8=D0=BA, 5 =D0=B8=D1=8E=D0=BB=D1=8F 2016 =D0=B3., 14:59= :06 UTC+7 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0= =BB=D1=8C Jonathan Coe =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB:
Thank= s for suggesting this, I'm afraid I don't think I like this idea.

It saves a bit of typing but would make it less cle= ar what's going on and in cases where a function signature changes woul= d change the meaning of existing code without any edits being made

f(A a);

Changed to

=
f(B b);

Would change the meaning of=C2= =A0

f(dynamic_cast(x));

I= n a rather non-obvious way.

Regards

=
Jon

--
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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/00caca39-d36a-475c-840f-79759e99265d= %40isocpp.org.
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