220 32815 <1cdd0fbf-c65d-4034-82d1-a84d4c4f6d1c@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Halfdan Ingvarsson Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: std::enum Date: Tue, 20 Jun 2017 20:34:28 -0700 (PDT) Lines: 244 Approved: news@gmane.org Message-ID: <1cdd0fbf-c65d-4034-82d1-a84d4c4f6d1c@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_4754_1603844511.1498016068257" X-Trace: blaine.gmane.org 1498016069 13046 195.159.176.226 (21 Jun 2017 03:34:29 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 21 Jun 2017 03:34:29 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBD5MZ4NLUIMRBRGSU7FAKGQEAYCLN5Q@isocpp.org Wed Jun 21 05:34:25 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ot0-f199.google.com ([74.125.82.199]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dNWPQ-0003A3-Nr for gclcip-std-proposals@m.gmane.org; Wed, 21 Jun 2017 05:34:25 +0200 Original-Received: by mail-ot0-f199.google.com with SMTP id v16sf29412995ote.7 for ; Tue, 20 Jun 2017 20:34:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:subject:mime-version:x-original-sender :reply-to:precedence:mailing-list:list-id:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=EcUmE1pZ2bGHaK5pacKCT/mDrutDunBbduQaHqtBxYU=; b=n1XUsti9vs1jsEBp8qlD476QiQLonYy63vZD9Tu6YeiuiJ8mDvuPQZOzn0R2fvMiVl xie9YHSGtvkxViwQMEfavmYTZi3mCZyYnUNpmPx8hciwVOAXNe8YM+ig4sMEy2OQUvmM JPM+Fl1fuTuIOgCzco7EukA+UBc1PzBM8puDZlLnQoF7f8UIsTaTwHhrYVK18/1DYNRE FALBT+Ul69DXG18wz8MB7WPEB5C2m2HdRvZ9MHOaM2VXEDF+m/iG4ImWNrEL5U9m6EsE BlU6vTtnJN1otlzjb8kuPBy3xdz19wJuarzAdVSVLUReODIBlTMAI17IPf8y6xpEolGt H1mQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:subject:mime-version:x-original-sender :reply-to:precedence:mailing-list:list-id:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=EcUmE1pZ2bGHaK5pacKCT/mDrutDunBbduQaHqtBxYU=; b=OQkBohQdwA0UReKg3MeORmA2q0ZwPbDFQX43Bjig6KBmUJnP2zRvWPtUV/3r+bTVzh mz7CYH/6mB57f/DCjAbSMXICNHeQoMwrI92ZqE6yWsFczc8X1n8iiu1nh0Cgp+ja2BwF 7ojU3B7vtJmzpLUKhXicYrsodX3Mu9VtfVLFR6rRvssEhgf59AJ48qH/sSvP9EFdEYYb DCNROiRCbcF8dF/14RKwhwYuSeNRPIdZriTPLsKMZF53w+UR6UwBAoBvx3BGsyC6rl4o UXyjkH8tiyrJmZTU7RoTdBbZ3SjA7jiu5Pckya3hMIzlt1xb2txQr1G1W+q/GrnEcrSp K5vQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:subject:mime-version :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=EcUmE1pZ2bGHaK5pacKCT/mDrutDunBbduQaHqtBxYU=; b=Q/84MlVTKRbVWotLPlS+D8PUM5UuS2g0hvwvY0DRdvDNku8yHcwKZVVb2h3VhCs3JH yBz2KimNzp5QusMD2klHHQjaP29+XAgn/ULi+a7/DyPgMFHOERqj5MP9ZFVj6x5a38Mh 12pFCMubYkY/qCxwPaXiIGq2HmNc3GAoUFPQEVAFIJ5QPzEELFhgOsftV2ybe4qTmVrT 1GbQhs9phWB+zLrJpxjfHA1ePtPhnwHpHOCLDxsKL8ld5YgDvHh/urkvUXGpjiF6KoN3 aVXrIW+YXhgHhfH2RsPjE+2jcRGb+AXCEBZ41SGoJ3bJubVsYV63r9U9qYt8FoOmd8rd wFeg== X-Gm-Message-State: AKS2vOx+f+Ay8V/7WD0wLOTQ3517LSZAWLoEiRlC4/Yqn908YlXBHNAg GziqNCvi64RwpBRB X-Received: by 10.157.5.209 with SMTP id 75mr4238150otd.47.1498016069636; Tue, 20 Jun 2017 20:34:29 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.12.226 with SMTP id o31ls2895037otd.2.gmail; Tue, 20 Jun 2017 20:34:28 -0700 (PDT) X-Received: by 10.157.83.13 with SMTP id g13mr545564oth.10.1498016068721; Tue, 20 Jun 2017 20:34:28 -0700 (PDT) X-Original-Sender: halfdan@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:32815 Archived-At: ------=_Part_4754_1603844511.1498016068257 Content-Type: multipart/alternative; boundary="----=_Part_4755_878829838.1498016068258" ------=_Part_4755_878829838.1498016068258 Content-Type: text/plain; charset="UTF-8" I'd like to propose a simple, but very useful utility class for the standard library: std::enum. All it does is take a template parameter, which would be an enum type. It would then allow you to access the individual elements of that enum, in order of declaration, using a nearly identical interface as std::array<> (i.e either through enumerators, or operator[]). E.g: #include #include #include enum Color { Red = 1, Green = 2, Blue = 23 }; int main() { auto e = std::enum(); for( auto v: e) { std::cout << "Elem: " << v << "\n"; } std::cout << "Size: " << e.size() << "\n"; std::cout << "Largest: " << std::max_element(e.begin(), e.end()) << "\n"; return 0; } Output: Elem: 1 Elem: 2 Elem: 23 Size: 3 Largest: 23 I assume that this would have to take some form of a help from the compiler, similar to how std::underlying_type is implemented. However, this would obviate the current set of hacks that either require macros, special class constructions, or other inconvenient forms. -- 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/1cdd0fbf-c65d-4034-82d1-a84d4c4f6d1c%40isocpp.org. ------=_Part_4755_878829838.1498016068258 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I'd like to propose a simple, but very useful utility = class for the standard library: std::enum. =C2=A0

All it= does is take a template parameter, which would be an enum type.
=
It would then allow you to access the individual elements of= that enum, in order of declaration, using a nearly identical interface as = std::array<> (i.e either through enumerators, or operator[]).

E.g:=C2=A0

#include <iostream>
#include <enum>
#include <algorithm>


enum Color { Red =3D 1, Green =3D 2, Blue= =3D 23 };


int main()
{
=C2= =A0 =C2=A0= auto e =3D std::enum<Color>();
=C2=A0 =C2=A0for( auto v<= /span>: e)
=C2=A0 =C2=A0{
=C2=A0 =C2=A0 =C2=A0std::cout << "Elem: " << v << "\n";
=C2=A0 =C2=A0}
=C2=A0 =C2=A0std::cout = << <= /span>"Size:= " << e.size() << "\n";
=C2=A0 =C2=A0std::cout <<= "Lar= gest: " <<= ; std::max_element(e.begin(), e.end= ())= << "\n";
=C2=A0 =C2=A0return 0;
}
Output:
Elem: 1
Elem: = 2
Elem: 23
Size: = 3
Largest<= span style=3D"color: #660;" class=3D"styled-by-prettify">: 23

I assume that this= would have to take some form of a help from the compiler, similar to how s= td::underlying_type is implemented. However, this would obviate the current= set of hacks that either require macros, special class constructions, or o= ther inconvenient forms.

--
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To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+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/1cdd0fbf-c65d-4034-82d1-a84d4c4f6d1c= %40isocpp.org.
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