220 3789 <2b72b613-965d-4273-898e-871dad3db413@isocpp.org> article Path: news.gmane.org!not-for-mail From: Mikhail Semenov Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Dynamic Arrays: simple syntax Date: Sat, 20 Apr 2013 12:58:38 -0700 (PDT) Lines: 75 Approved: news@gmane.org Message-ID: <2b72b613-965d-4273-898e-871dad3db413@isocpp.org> References: <5ddeccbe-40d0-4894-afc5-c0105136b5d7@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_405_25498625.1366487919073" X-Trace: ger.gmane.org 1366487919 12152 80.91.229.3 (20 Apr 2013 19:58:39 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 20 Apr 2013 19:58:39 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDC55PNFRYGRB4HGZOFQKGQEGGHJKVY@isocpp.org Sat Apr 20 21:58:43 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ye0-f199.google.com ([209.85.213.199]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1UTdvn-0008Ge-1e for gclcip-std-proposals@m.gmane.org; Sat, 20 Apr 2013 21:58:43 +0200 Original-Received: by mail-ye0-f199.google.com with SMTP id l14sf8075264yen.6 for ; Sat, 20 Apr 2013 12:58:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:x-beenthere:x-received:date:from:to:message-id :in-reply-to:references:subject:mime-version:x-original-sender :reply-to:precedence:mailing-list:list-id:x-google-group-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=x/9QkpWBO86bYVIfBrkZqTc7CqROT3AcRGkurtwwMq4=; b=DCHjSt9FfXxpZv/JAsN/4rma+mUsl309qzZBpU3Y//MHKpl35yHiY+a8gHXaDNQk2E ghjrnJ9xaE3vdeFhQAhF5uPJ2Bpbp52+hRXDUQ/C14PV5W+hnYw6v6P6VlJAN3mFMl5d rKXUlJtY/kNDvo3e7xsybcFd+IQK6FPV7MH+0pW2g0n76FFdtGH5VWSxlvuul74EPDZv A1EW3HZcEKwfDCkb+mtqCTibtW4/NxnNtsOv8UOITcamciAv6la7WjBcuAR4BvzKaPtk 1Pz4Tguz9ZU6wuoc8PolLA5u4Pld17LkS53CkkAp8lIsj6qcJlqIPavfm/IxpAJq8nan 44fQ== X-Received: by 10.224.178.205 with SMTP id bn13mr14751344qab.3.1366487922215; Sat, 20 Apr 2013 12:58:42 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.49.35.39 with SMTP id e7ls2751686qej.58.gmail; Sat, 20 Apr 2013 12:58:39 -0700 (PDT) X-Received: by 10.49.4.169 with SMTP id l9mr579950qel.29.1366487919541; Sat, 20 Apr 2013 12:58:39 -0700 (PDT) In-Reply-To: X-Original-Sender: mikhailsemenov1957@gmail.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:3789 Archived-At: ------=_Part_405_25498625.1366487919073 Content-Type: text/plain; charset=ISO-8859-1 The sizeof() is statically defined; there is no way to define it properly dynamically. It is possible to forbid the assignment altogether, but the efficiency will be lost in some cases. Another approach is not to allow default assignment, but to allow operator= to be defined by the user, which may check for the sizes (sizes can be stored as class members) and produce an exception when they don't match. Anyway, these are the details that can be addressed. On Saturday, April 20, 2013 7:39:08 PM UTC+1, DeadMG wrote: > So, just to summarize: > > - You want a sizeof() that doesn't actually represent the size of the > object. > - You want operator= to be enabled or disabled based on a run-time > variable. > > Neither of these are possible. > -- --- 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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/?hl=en. ------=_Part_405_25498625.1366487919073 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
The sizeof() is statically defined; there is no way to define it prope= rly dynamically.
It is possible to forbid the assignment altogeth= er, but the efficiency will be lost in some cases.
 
Another approach is not to allow default assignment, but to allow operat= or=3D to be defined by the user, which may check for the sizes (sizes can b= e stored as class members) and produce an exception when they don't match.<= /div>
Anyway, these are the details that can be addressed.
&= nbsp;

On Saturday, April 20, 2013 7:39:08 PM UTC+1, DeadMG wr= ote:
So, just to summarize:
  • <= span style=3D"line-height: normal;">You want a sizeof() that doesn't actual= ly represent the size of the object.
  • You want operator=3D to be enabled or disabled based on a run= -time variable.
Neither of these are possible.

--
 
---
You received this message because you are subscribed to the Google Groups &= quot;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-pro= posals/?hl=3Den.
 
 
------=_Part_405_25498625.1366487919073-- .