220 18934 <88bd4cab-a13d-41ef-813c-e931c0b95226@isocpp.org> article Path: news.gmane.org!not-for-mail From: Edward Catmur Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Unified coercion protocol: static_cast explicit overload Date: Thu, 2 Jul 2015 03:38:09 -0700 (PDT) Lines: 94 Approved: news@gmane.org Message-ID: <88bd4cab-a13d-41ef-813c-e931c0b95226@isocpp.org> References: <5c654bc3-5294-4f8a-bf1a-bf4a9f6c8603@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_216_1050109078.1435833489443" X-Trace: ger.gmane.org 1435833493 25793 80.91.229.3 (2 Jul 2015 10:38:13 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 2 Jul 2015 10:38:13 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDZLZTXF7UJBBEVJ2SWAKGQELZBB4VY@isocpp.org Thu Jul 02 12:38:13 2015 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pd0-f197.google.com ([209.85.192.197]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZAbsi-0007Zt-Fl for gclcip-std-proposals@m.gmane.org; Thu, 02 Jul 2015 12:38:12 +0200 Original-Received: by pdzq9 with SMTP id q9sf159047188pdz.3 for ; Thu, 02 Jul 2015 03:38:11 -0700 (PDT) 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:message-id:in-reply-to:references :subject:mime-version:content-type: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=DgapF7VfdAR9cTPOr/JI4s78ULXcaQ43BZ6HH4JEBFk=; b=FEDYpe5sQzFjFiN9HF2AeqcJefmP4uGaMN8gOpHrpz6EvlQZos6SIeZfW4OWRWL6QA qsa8zQ4KuDkfV165kHmnO1+ZRzgPst+EfzG/dE1KJCg+2DfZq+VSdvDIlgMlybu3mbhl vMzpZZHSwoYit1kYCqx6rMIDTfTd0suv3J4iErFhV+MsuewbFCyJLBH4MtPv3pu3s3jF TXFc41MVymMaKgMODtjHoSMEiWCXLCnvZ0VW+747ALySZyPfsdMQRrV3rb1DOqBciVgP fyrp2jfhwCjLatBjPD7eAsgZ9UhidL+1LrVtHTtXYd/dV8cNn1s3h7IqfeHX4sIUFtBr N5VQ== X-Gm-Message-State: ALoCoQl2Xoi9Mr/dkSPrMXmUEedNFpTrg18IOPYu5g3jz3UlfHwKqvQUsc6sVpyRf+Usp9RkG80F X-Received: by 10.67.6.196 with SMTP id cw4mr39942544pad.46.1435833491514; Thu, 02 Jul 2015 03:38:11 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.16.173 with SMTP id 42ls1225420qgb.47.gmail; Thu, 02 Jul 2015 03:38:10 -0700 (PDT) X-Received: by 10.140.94.166 with SMTP id g35mr160259qge.1.1435833490011; Thu, 02 Jul 2015 03:38:10 -0700 (PDT) In-Reply-To: X-Original-Sender: ed@catmur.co.uk 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:18934 Archived-At: ------=_Part_216_1050109078.1435833489443 Content-Type: multipart/alternative; boundary="----=_Part_217_1162662900.1435833489443" ------=_Part_217_1162662900.1435833489443 Content-Type: text/plain; charset=UTF-8 On Wednesday, 1 July 2015 14:55:52 UTC+1, Igor Baidiuk wrote: > > I cannot define conversions as free-standing functions. > Sometimes it's really useful when you want those conversions, but don't > want to pollute struct interface, because those conversions are used only > inside of some module. > Also when defining vocabulary type interoperations; I might have a Date type that I want to be able to convert to/from Boost.Gregorian, but I don't want to impose a dependency on clients that don't need the interop. The easiest way to write this would be to allow non-member conversion functions: explicit operator To(From const& from) { ... } I think this was raised in passing here last year, although without much result: https://groups.google.com/a/isocpp.org/forum/#!topic/std-proposals/CmBERU_sr8Y -- --- 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/. ------=_Part_217_1162662900.1435833489443 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On Wednesday, 1 July 2015 14:55:52 UTC+1, Igor Baidiuk wr= ote:
I cannot = define conversions as free-standing functions.
Sometimes it's really use= ful when you want those conversions, but don't want to pollute struct inter= face, because those conversions are used only inside of some module.

Also when defining vocabulary type inte= roperations; I might have a Date type that I want to be able to convert to/= from Boost.Gregorian, but I don't want to impose a dependency on clients th= at don't need the interop.

The easiest way to writ= e this would be to allow non-member conversion functions:

explicit operator To= (From const& from) {= ... }

I think this was raised in passing here last year, although= without much result: https://groups.google.com/a/isocpp.org/forum/#!t= opic/std-proposals/CmBERU_sr8Y

--

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Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/<= /a>.
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