220 36669 <9d45f2d0-e2b7-4293-b293-6a558fd59b30@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Cleiton Santoia Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: operator[](...) Date: Tue, 16 Jan 2018 10:44:44 -0800 (PST) Lines: 93 Approved: news@gmane.org Message-ID: <9d45f2d0-e2b7-4293-b293-6a558fd59b30@isocpp.org> References: <8bbeac1f-f698-4e49-9e1f-4cb1ab389b09@isocpp.org> <3b13beef-4a63-1315-c11d-07ba04e6f9bd@gmail.com> <4d35c71c-cdc0-45de-976e-2f70b20695c0@isocpp.org> <5a504df3-7632-4035-9f94-7c72f0d094af@isocpp.org> <35b73d9f-8920-4282-927e-7c2f06c2b49c@isocpp.org> <4ab0ef05-5d80-441d-905e-7d25b53f7379@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_7864_14740634.1516128284183" X-Trace: blaine.gmane.org 1516128167 27048 195.159.176.226 (16 Jan 2018 18:42:47 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 16 Jan 2018 18:42:47 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCBMVWMTUUNBBHMQ7HJAKGQEZ6MCB4A@isocpp.org Tue Jan 16 19:42:43 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ua0-f198.google.com ([209.85.217.198]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ebWC2-0006cQ-N7 for gclcip-std-proposals@m.gmane.org; Tue, 16 Jan 2018 19:42:42 +0100 Original-Received: by mail-ua0-f198.google.com with SMTP id g30sf11706868uaf.18 for ; Tue, 16 Jan 2018 10:44:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; 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; bh=NB4IxdBbkq3VrGuaribIyPCpnZYl9wzViZnnt63YTzk=; b=fvIRj9r/2fJBQAxv/cuOstea0wHSCDvrrethdZ4UT9kZXNWbzxdcdpsJVI/vC45zMm RKpXIzmB/+7upQS9TdN7sFegWZQ5/plnK9G1FOsSXAgBHYuN05vdqPuxSFhcLcbDv3Q/ S05klWRfrVGoa11FymMC7I0+6gHarNuK40j35A3CUSxFzOh8AHwJmU0R/pgPkCKI9M6x 1LyHC8uHC1vRjBDxYOSnHb7vFBQIp8wHP2p7UxCTNnDcIfkOi+IwjWAGMwsizbBuZclt vG/6x8/QncQ8u/P3ITmx0xvcm8664rfUclEMM71y+WUntzCTOmHcL9u7PvPuM58L3dBj PCOA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; 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; bh=NB4IxdBbkq3VrGuaribIyPCpnZYl9wzViZnnt63YTzk=; b=uhDSChwx59iWAwlvbWZnsKojar+4z+UoSlE4mPQv+3dboTwZDLRrbCBLuJ0PpvntZ1 bbOCPGDxIMi/rVTecb1Ycnfqr1gaTGOehnUM2s0LwXisd/oeN/gkM6rGmVUyMjj1n4I+ bHAY6moDPXZhZs0dPCgJocLnep3mRvFB/z4xl7vSkjsliAEdP/OVBXF+7IlzVWyu1Vy9 W8NeCe8E5/PluAM8lN8qyDt5tkoiGt0IFtm0ciHZngcoHRfOa2mRXtlrVcH/RblO6uSZ eMslbqUay1F76CI4LF8nIegrpJ2UfNYYtb6RmKp6kgm5WK/5CgVSzrNxat+KoaI6RfFH sgTA== 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: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=NB4IxdBbkq3VrGuaribIyPCpnZYl9wzViZnnt63YTzk=; b=tVp8XD0nUaAvS6KzmQEEHNzs8xs7xsINeYnuKLr3HWWMFz1JKvvc4KFyOvFwsLZ6gM pRdRfirAh+1IyM7SuDD0k04SiVQw+tQMCOfLQ4aIwvlKT5yvwHzjt2QwM2GLMNbmWRux PuIvM2sIJFTuPZ8QMvrnBoVVEPNnn7IJZtRbPfCYYVFG9CCeD7D94D2SMPCUkUZwtNZ7 enFm2h3HoVhcDYbGkZ6f00/FIvCg6qJ36ofCoL236sFcF2Ua9NBhJY/Coax6LdFjLxCS mOri06SbPzhDfdW+RPb7CE5hL6gjWN+HhBPZKj+jQmogI8VaixAmOu/CPdNQ9WiiOlme A0HQ== X-Gm-Message-State: AKwxytfgCCZwp1r4MubKQ/ed6z++zAzlD7NrpTgYyVQkkIn0KpzfwD9u sG8kvq804I6haMmH2hRovZoIZQ== X-Google-Smtp-Source: ACJfBou1yGmLqNCGylYY0fApBU93lvWF8m9eXlSPe/LiUI8dRRG9jJiKL/eO5cHw0+HajtOuYFAqnA== X-Received: by 10.176.49.84 with SMTP id e20mr79124uam.11.1516128286373; Tue, 16 Jan 2018 10:44:46 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.31.157.1 with SMTP id g1ls1034307vke.7.gmail; Tue, 16 Jan 2018 10:44:44 -0800 (PST) X-Received: by 10.31.147.5 with SMTP id v5mr11581vkd.5.1516128284756; Tue, 16 Jan 2018 10:44:44 -0800 (PST) In-Reply-To: X-Original-Sender: cleitonsantoia@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:36669 Archived-At: ------=_Part_7864_14740634.1516128284183 Content-Type: multipart/alternative; boundary="----=_Part_7865_1390534653.1516128284184" ------=_Part_7865_1390534653.1516128284184 Content-Type: text/plain; charset="UTF-8" I think that c++ behavior of obj[x,y] is awkward. When using this syntax, GCC already warn us: main.cpp:24:10: warning: left operand of comma operator has no effect [-Wunused-value] Other contexts that [] can appear (lambdas or bindings), the x and y are two different things passed to wherever [] will do, only in operator[] it's is allowed this "pay two and get one" parameter passing. This is a little embarrassing to explain... Regardless of new uses for operator[]. I'm pro deprecate this. Said that, easily follows that multi-parameter may use same rules as multi-parameter operator(). How about this (admittedly offbeat) syntax: > > x[1; 2; 3] // use semicolons to separate multidimensional indexes > This is strange, what happens if someone tries x[1,2,3;2;3,2,1] ? mixing ',' and ';' ? -- 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/9d45f2d0-e2b7-4293-b293-6a558fd59b30%40isocpp.org. ------=_Part_7865_1390534653.1516128284184 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

I think that c++ behavior of obj[x,y] = is awkward.=C2=A0

When using this syntax, GCC alre= ady warn us:
main.cpp:24:10: warning: left operand of comma operator has n= o effect [-Wunused-value]

Other contexts= that [] can appear (lambdas or bindings), the x and y are two different th= ings passed to wherever [] will do, only in operator[] it's is allowed = this "pay two and get one" parameter passing. This is a little em= barrassing to explain...

Regardless of new use= s for operator[]. I'm pro deprecate this.

Said= that, easily follows that multi-parameter may use same rules as multi-para= meter operator().





How about this (admittedly offbeat) syntax:
=C2=A0 =C2=A0 x[1; 2; 3]=C2=A0 =C2=A0 // use semicolons t= o separate multidimensional indexes

=
=C2=A0This is strange, what happens if someone tries x[1,2,3;2;3,2,1] = ? mixing ',' and ';' ?

=C2=A0

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