220 33568 <58cf0b51-dc02-e7f8-43a0-8bcf1714e803@honermann.net> article Path: news.gmane.org!.POSTED!not-for-mail From: Tom Honermann Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Add type alias that mirrors given type Date: Thu, 3 Aug 2017 11:37:39 -0400 Lines: 114 Approved: news@gmane.org Message-ID: <58cf0b51-dc02-e7f8-43a0-8bcf1714e803@honermann.net> References: <20f365ce-2a24-4576-894f-923e7b9cd76e@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="------------1C58BEB03CAA1C0C5330EA98" X-Trace: blaine.gmane.org 1501774668 10673 195.159.176.226 (3 Aug 2017 15:37:48 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 3 Aug 2017 15:37:48 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDBNXSHG6UDBBREGRXGAKGQEO52DBBQ@isocpp.org Thu Aug 03 17:37:42 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-it0-f69.google.com ([209.85.214.69]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ddIBs-0002AB-F2 for gclcip-std-proposals@m.gmane.org; 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[108.166.43.83]) by mx.google.com with ESMTPS id 10si1205390iol.393.2017.08.03.08.37.40 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Aug 2017 08:37:40 -0700 (PDT) Received-SPF: neutral (google.com: 108.166.43.83 is neither permitted nor denied by best guess record for domain of tom@honermann.net) client-ip=108.166.43.83; Original-Received: from smtp19.relay.ord1c.emailsrvr.com (localhost [127.0.0.1]) by smtp19.relay.ord1c.emailsrvr.com (SMTP Server) with ESMTP id D4FB0A06B8 for ; Thu, 3 Aug 2017 11:37:39 -0400 (EDT) X-Auth-ID: tom@honermann.net Original-Received: by smtp19.relay.ord1c.emailsrvr.com (Authenticated sender: tom-AT-honermann.net) with ESMTPSA id A5C3FA05C4 for ; Thu, 3 Aug 2017 11:37:39 -0400 (EDT) X-Sender-Id: tom@honermann.net Original-Received: from [192.168.1.15] (pool-173-53-30-126.rcmdva.fios.verizon.net [173.53.30.126]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA) by 0.0.0.0:587 (trex/5.7.12); Thu, 03 Aug 2017 11:37:39 -0400 In-Reply-To: <20f365ce-2a24-4576-894f-923e7b9cd76e@isocpp.org> X-Original-Sender: tom@honermann.net X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 108.166.43.83 is neither permitted nor denied by best guess record for domain of tom@honermann.net) smtp.mailfrom=tom@honermann.net 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:33568 Archived-At: This is a multi-part message in MIME format. --------------1C58BEB03CAA1C0C5330EA98 Content-Type: text/plain; charset="UTF-8"; format=flowed On 08/02/2017 03:27 PM, Antonio Perez wrote: > I propose that a type alias which simply returns the given type be > added to the standard library for the purpose of working with types > whose syntax is problematic. > > The definition could be as follows: > > | > templateusingtypemirror =T; > | |This template is typically called identity (or identity_t) and is also useful for disabling type deduction. It might be worth trying to standardize it, but there is prior history to be aware of: https://groups.google.com/a/isocpp.org/forum/#!topic/std-proposals/vrrtKvA7cqo Tom.| -- 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/58cf0b51-dc02-e7f8-43a0-8bcf1714e803%40honermann.net. --------------1C58BEB03CAA1C0C5330EA98 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On 08/02/2017 03:27 PM, Antonio Perez wrote:
I propose that a type alias which simply returns the given type be added to the standard library for the purpose of working with types whose syntax is problematic.

The definition could be as follows:

template<class T> using typemirror =3D T;
This template is typically called identity (or identity_t) and is also useful for disabling type deduction.

It might be worth trying to standardize it, but there is prior history to be aware of:

https://groups.google.com/a= /isocpp.org/forum/#!topic/std-proposals/vrrtKvA7cqo

Tom.

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