220 37727 article Path: news.gmane.org!.POSTED!not-for-mail From: "'Matt Calabrese' via ISO C++ Standard - Future Proposals" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Generic function-wrapper object Date: Mon, 09 Apr 2018 15:46:30 +0000 Lines: 180 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="94eb2c05b49ee859d905696c4f42" X-Trace: blaine.gmane.org 1523288679 17911 195.159.176.226 (9 Apr 2018 15:44:39 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 9 Apr 2018 15:44:39 +0000 (UTC) To: "ISO C++ Standard - Future Proposals" Original-X-From: std-proposals+bncBCGNLO5F34OBBYUVV3LAKGQEZVRD22A@isocpp.org Mon Apr 09 17:44:35 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-io0-f197.google.com ([209.85.223.197]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1f5YyA-0004Xp-FN for gclcip-std-proposals@m.gmane.org; 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[209.85.220.41]) by mx.google.com with SMTPS id v98sor333623iov.37.2018.04.09.08.46.42 for (Google Transport Security); Mon, 09 Apr 2018 08:46:42 -0700 (PDT) Received-SPF: pass (google.com: domain of calabrese@google.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 10.107.171.194 with SMTP id u185mr32884101ioe.234.1523288801504; Mon, 09 Apr 2018 08:46:41 -0700 (PDT) In-Reply-To: X-Original-Sender: calabrese@google.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=rq5MJfnp; spf=pass (google.com: domain of calabrese@google.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=calabrese@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com X-Original-From: Matt Calabrese 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:37727 Archived-At: --94eb2c05b49ee859d905696c4f42 Content-Type: text/plain; charset="UTF-8" On Mon, Apr 9, 2018 at 11:36 AM Hamza Sood wrote: > I propose the inclusion of a function object (somewhat similar to the > deprecated ptr_fun) that looks something like: > > template > requires is_pointer_v && > is_function_v> > struct func_ptr { > template > decltype(auto) operator()(Args&&... args) noexcept(noexcept(f(forward< > Args>(args)...))) { > return f(forward(args)...); > } > }; > > The main difference with ptr_fun being that the function pointer is part > of the type. > I have proposed something like that here: http://wg21.link/p0477 It is awaiting a revision with some different names, and I will need to update it to target C++20 (updated constraints, etc.). -- Matt Calabrese -- 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/CANh8DEk7X8whB5K5GNQai2r9gt52HKEVtxE6aGy78w_%2Bp20BTQ%40mail.gmail.com. --94eb2c05b49ee859d905696c4f42 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

On Mon, Ap= r 9, 2018 at 11:36 AM Hamza Sood <h= amza_sood@me.com> wrote:
I propose the inclusion of a function obje= ct (somewhat similar to the deprecated ptr_fun) that looks something like:<= div>
templa= te<auto f>
requires is_poi= nter_v<decltype(f)> &&=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is_function_v&l= t;remove_pointer_t<= decltype(f<= /span>)>>
struct func_ptr {
=C2=A0 template<typename... Args&g= t;
=C2=A0 decltype(auto) operator()(= Args&&...<= span style=3D"color:rgb(0,0,0)" class=3D"gmail-m_-767131349022434533styled-= by-prettify"> args) noexcept<= /span>(noexcept(f(forward<Args>(args= )...))) {
=C2=A0 =C2=A0 return f(forward<Args>(args)...);
=C2=A0 }
};

The main difference with ptr_fun being that the function pointe= r is part of the type.

I have proposed something like that here:=C2=A0http://wg21.link/p0477

It = is awaiting a revision with some different names, and I will need to update= it to target C++20 (updated constraints, etc.).

-= - Matt Calabrese

--
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