220 9237 <848819e9-04cf-42b6-9ee6-13cf2ff6dc95@isocpp.org> article Path: news.gmane.org!not-for-mail From: Bengt Gustafsson Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Comments on 2d api for c++ N3888.pdf Date: Sun, 9 Feb 2014 15:12:18 -0800 (PST) Lines: 157 Approved: news@gmane.org Message-ID: <848819e9-04cf-42b6-9ee6-13cf2ff6dc95@isocpp.org> References: <9105f9b2-e15d-4bf8-a4a1-65ebc3657eb0@isocpp.org> <1499411.eehuFWK7Yv@tjmaciei-mobl2> <8a29e404-8218-4853-9db9-d4030709ab43@isocpp.org> <6822200.TbR7qDM6I7@tjmaciei-mobl4> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_2661_7413169.1391987538228" X-Trace: ger.gmane.org 1391987537 10697 80.91.229.3 (9 Feb 2014 23:12:17 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 9 Feb 2014 23:12:17 +0000 (UTC) Cc: thiago@macieira.info To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCRIRSPDTQIRBUUW4CLQKGQEPZYCNOY@isocpp.org Mon Feb 10 00:12:24 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yk0-f199.google.com ([209.85.160.199]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WCdXw-00018i-Cv for gclcip-std-proposals@m.gmane.org; Mon, 10 Feb 2014 00:12:20 +0100 Original-Received: by mail-yk0-f199.google.com with SMTP id 10sf12489214ykt.2 for ; Sun, 09 Feb 2014 15:12:19 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; 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:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=1LuaBqIiyFf/xqBN0/2OPKgtjwr7iUWiSx6BBB4dP7Q=; b=EfpJU9DxHK61HI3tGIlQETvbWcWx2qEfmc5Ri5CKcWcI5Mov0Uqyxjh12FbFKcxvno +FDp5QrhQoIcSTRmFz+Re5tjYQ8koodAXubnOZzbJnvtK+EneOTWicZXUnQhiu9dZV6P yhnJE41SoVHmdKTAkOlLp6ZWEDDjosWp7YEyvMD0XMeq4sHMqWaZxm8nPvszCNdWXojh 0+KmRcwS9BX9OgLfU4O1a8q2o1X5oKkCKQKm6wSB7/3CkfGu7y24+D/5YMilv8rAVgsG 8vng4qowzQG3iE2yKi3YGNmKllbXidfk80ms+RwU9vNMGQ7pRzbXKb9bsanWAYn45EbB a2pA== X-Gm-Message-State: ALoCoQlcxO7cIxMvIrpZqUhi4bTtM2OgLLkO2pZzsvsU14WLEOkLymgVSJTy8o5ZDhIBpzTLBTi/ X-Received: by 10.52.29.16 with SMTP id f16mr9518843vdh.8.1391987539219; Sun, 09 Feb 2014 15:12:19 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.108.135 with SMTP id j7ls1809130qgf.88.gmail; Sun, 09 Feb 2014 15:12:18 -0800 (PST) X-Received: by 10.140.94.11 with SMTP id f11mr578267qge.7.1391987538622; Sun, 09 Feb 2014 15:12:18 -0800 (PST) In-Reply-To: <6822200.TbR7qDM6I7@tjmaciei-mobl4> X-Original-Sender: bengt.gustafsson@beamways.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:9237 Archived-At: ------=_Part_2661_7413169.1391987538228 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable The compiler will definitely inline those trivial adaptor methods which=20 look like this or very similar: getx(const my_point& p) { return p.x; } It won't generate any object code bloat at all. The alternative, using a=20 std::drawing specific point class will however require creating a temprary= =20 object which in some cases is harder to optimize away, and introduces a lot= =20 of SOURCE code bloat: dc.draw_point(std::drawing::point(p.x, p.y)); instead of: dc.draw_point(p); I think this is quite compelling! By the way: Drawing methods such as draw_polygon which take a range of=20 points can also be written to accept diffrerent types of points, although= =20 it will be harder to optimize away copying of data, depending on the=20 underlying "device driver" implementation. Den m=C3=A5ndagen den 3:e februari 2014 kl. 05:54:32 UTC+1 skrev Thiago Mac= ieira: > > Em dom 02 fev 2014, =C3=A0s 20:14:20, Bengt Gustafsson escreveu:=20 > > About method overloads that take point or rect types. I now came to the= =20 > > conclusion that we should have a template overload to cater for "all"= =20 > types=20 > > of point classes the user of the library may have on hand. Can this be= =20 > > done? Yes:=20 > > Should it be done? IMHO, no.=20 > > Making an entirely-template API means potentially a lot of code bloat. It= =20 > means all of the actual API is implemented in private APIs, called by=20 > inline=20 > template methods.=20 > > > C++ provides many tools, we must try to use all of them appropriately!= =20 > > Appropriately also implies that there are conditions under which some=20 > tools=20 > must not be used. I believe this to be one of them.=20 > > --=20 > Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org=20 > Software Architect - Intel Open Source Technology Center=20 > PGP/GPG: 0x6EF45358; fingerprint:=20 > E067 918B B660 DBD1 105C 966C 33F5 F005 6EF4 5358=20 > > --=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/. ------=_Part_2661_7413169.1391987538228 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The compiler will definitely inline those trivial adaptor = methods which look like this or very similar:

getx(const= my_point& p) { return p.x; }

It won't generat= e any object code bloat at all. The alternative, using a std::drawing speci= fic point class will however require creating a temprary object which in so= me cases is harder to optimize away, and introduces a lot of SOURCE code bl= oat:

dc.draw_point(std::drawing::point(p.x, p.y));=

instead of:

dc.draw_poin= t(p);

I think this is quite compelling!
=
By the way: Drawing methods such as draw_polygon which take = a range of points can also be written to accept diffrerent types of points,= although it will be harder to optimize away copying of data, depending on = the underlying "device driver" implementation.

Den m=C3=A5ndagen den 3:e februari 2014 kl. 05:54:32 UTC+1 skrev Thia= go Macieira:
Em dom 02 fev 2014= , =C3=A0s 20:14:20, Bengt Gustafsson escreveu:
> About method overloads that take point or rect types. I now came t= o the
> conclusion that we should have a template overload to cater for "a= ll" types
> of point classes the user of the library may have on hand. Can thi= s be
> done? Yes:=20

Should it be done? IMHO, no.

Making an entirely-template API means potentially a lot of code bloat. = It=20
means all of the actual API is implemented in private APIs, called by i= nline=20
template methods.

> C++ provides many tools, we must try to use all of them appropriat= ely!

Appropriately also implies that there are conditions under which some t= ools=20
must not be used. I believe this to be one of them.

--=20
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel Open Source Technology Center
      PGP/GPG: 0x6EF45358; fingerprint:
      E067 918B B660 DBD1 105C  966C 33F5 F005 6EF4= 5358

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