220 37376 <8fdfc016-2eb8-4888-9531-66310c80b457@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Jakob Riedle Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: `offsetof` in a macro-less, modular world Date: Sat, 17 Mar 2018 03:11:11 -0700 (PDT) Lines: 86 Approved: news@gmane.org Message-ID: <8fdfc016-2eb8-4888-9531-66310c80b457@isocpp.org> References: <6725bbc8-a8db-40e1-a3f4-98ac05e23862@isocpp.org> <3998341.rfsqbO5A2U@tjmaciei-mobl1> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_4263_1238526659.1521281471848" X-Trace: blaine.gmane.org 1521281361 18615 195.159.176.226 (17 Mar 2018 10:09:21 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 17 Mar 2018 10:09:21 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCX2XNFO6MPRBQOTWPKQKGQEPK2JQOY@isocpp.org Sat Mar 17 11:09:17 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-vk0-f69.google.com ([209.85.213.69]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ex8m0-0004Yq-7c for gclcip-std-proposals@m.gmane.org; Sat, 17 Mar 2018 11:09:12 +0100 Original-Received: by mail-vk0-f69.google.com with SMTP id y20sf7904398vkd.12 for ; Sat, 17 Mar 2018 03:11:14 -0700 (PDT) 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=ntBywPqP+7L1xayTnpK4xG7BCwFBOHLVcSwUu31jMc8=; b=1YDrGOVglVUvF3z+cVEtCZsZrmGIxOq9XsU5DVIxc7uG5Iy82fbad6eFHaxyeIdSXI dVSzQ6Cf2SiZO1ibk11Y+Mk9Tg4IarhpJNaCybbWyOgBqVP98OpBOFP71Ep5HtXEo5SJ 9bgehAUj5pJj23E8aTP5jliLYuxYneVNHaOqKe9jMMBAv44tfUzKq/FfX/V5SM6i4xVE iSx31qZFy1K9y0kduDdd+Gfk20ofmArousE1uwpOPUGqK5Jj2Bprfp93kfdmaDAboxjX yAztcL/oeAY6D9oWT0qYs/CUYbAazbnnoXJPH0RaTDSdTW4NB6cBb79HY+41bpxZvTpP Ng/Q== 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=ntBywPqP+7L1xayTnpK4xG7BCwFBOHLVcSwUu31jMc8=; b=CpituT2CdEMkWBNG147GgHsO28IwiS+JW+l6q2fuha9QkJpfNokgXosVCXATdY3iO0 l6kyATG03YwVdxYCZMI6ixn+sBoaXGfxNbLlZxC/DwLQs938uQk6DmrCML9ZJjoUqtdv ZXzSPYdV0LAj1zDeiJm0KTUaIECAw5ZHu0vqzQS8Ky2vxf0rv1A3v4FO80XdniUi8b6y 5x1kOPwDpBjvRtDR2Cz2vqWdv3OdOuZPbK9p2jZSGVei7Gf3TQaGjvJsO7WPLxwgw49y E2UCWlSHV66JS9HbTAjS+GXTdNtAVWgXUKANfNJ5h9HE0WFK8X5op/uTVrYC4PA9gpLH fIQA== 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=ntBywPqP+7L1xayTnpK4xG7BCwFBOHLVcSwUu31jMc8=; b=Vya7Vtx80z573rGwYoeJrwBr+6HIKNobICs52MPQam53l4aZU3TOaGSn1o8g0Ha3Yg WF5sOUSvJACPVDVUGSIClKIT1uF7lpb7N/c1m12saM8/nqbwYbq4SKNzZIYH4qRyVA/H a5OJz2vno+3XYwzTToTEeGjVXHpoNBOtSC0iaU/QBJDCKHvHilXd5qWy37Nyk/iiDSm7 gSTwoGGXYxgfZxGU6DSJOijhR2QiyoRW/olFLH3iyYC2ZFfxFc4nmh0u+N380ilUGneB po63KnKlQWofJb/WvUSObDw9qli1kWOEKZ0VRxCZFahWG4s4VDTmwhb57RP5ZnlZVw8Z Hklg== X-Gm-Message-State: AElRT7EPDGp2r7RXcsn5Wu7ZaCSFg+R/XvXWos6z+LuxKF8oly+nf/WX eEPxJ4aog0nQY9tAD11fONTIxQ== X-Google-Smtp-Source: AG47ELvQXRWESy4Y4o3AFNJ3ueQmtZCvFb42YwyLRVBXEGajs6VJndCh5Ys5FUbYW8r4vaV8Ra3oIQ== X-Received: by 10.159.54.36 with SMTP id r33mr2125761uad.2.1521281474069; Sat, 17 Mar 2018 03:11:14 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.31.146.138 with SMTP id u132ls4856922vkd.13.gmail; Sat, 17 Mar 2018 03:11:12 -0700 (PDT) X-Received: by 10.31.151.87 with SMTP id z84mr583432vkd.5.1521281472586; Sat, 17 Mar 2018 03:11:12 -0700 (PDT) In-Reply-To: <3998341.rfsqbO5A2U@tjmaciei-mobl1> X-Original-Sender: jakob.riedle@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:37376 Archived-At: ------=_Part_4263_1238526659.1521281471848 Content-Type: multipart/alternative; boundary="----=_Part_4264_1670575124.1521281471848" ------=_Part_4264_1670575124.1521281471848 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Am Samstag, 17. M=C3=A4rz 2018 05:32:36 UTC+1 schrieb Thiago Macieira: > > The first step would be to make a (quick) survey of C++ uses of offsetof= =20 > --=20 > that is, things that aren't just regular C code in C++ mode (think of=20 > Linux=20 > kernel's struct list[1]).=20 > Hi Thiago, as a first contribution to this survey :-), I recently used it to=20 determine, whether two attributes (used in two different memory layout=20 modes of a class) shaddow each other. Here is the link to the spot (Line 667): https://github.com/DuffsDevice/tinyutf8/blob/master/include/tinyutf8.h I found this macro very useful in this spot and I'd be fine to have it=20 replaced by a built-in feature. Hope this helps, Jakob --=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/8fdfc016-2eb8-4888-9531-66310c80b457%40isocpp.or= g. ------=_Part_4264_1670575124.1521281471848 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


Am Samstag, 17. M=C3=A4rz 2018 05:32:36 UTC+1 schr= ieb Thiago Macieira:
The first = step would be to make a (quick) survey of C++ uses of offsetof --=20
that is, things that aren't just regular C code in C++ mode (think = of Linux=20
kernel's struct list[1]).

Hi Thiago,

as= a first contribution to this survey :-), I recently used it to determine, = whether two attributes (used in two different memory layout modes of a clas= s) shaddow each other.
Here is the link to the spot (Line 667):

I found this macro very useful in= this spot and I'd be fine to have it replaced by a built-in feature.

Hope this helps,
Jakob

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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/8fdfc016-2eb8-4888-9531-66310c80b457= %40isocpp.org.
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