220 8665 <3a3d55c0-20cb-40ff-ae46-84663d21f44d@isocpp.org> article Path: news.gmane.org!not-for-mail From: gornishanov@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: string_view::is_null() Date: Fri, 17 Jan 2014 15:10:41 -0800 (PST) Lines: 54 Approved: news@gmane.org Message-ID: <3a3d55c0-20cb-40ff-ae46-84663d21f44d@isocpp.org> References: <8045a4d2-721d-4725-8bb7-7a91b6f53ec8@isocpp.org> <186E0927-C962-4E34-AED0-E7509DD1F0A0@gmail.com> <7aad44d8-6b4e-438a-b309-bd898b994b34@isocpp.org> <9C2C439F-7983-4224-B272-53CAD0E2E456@gmail.com> <8E74B747-7450-41E0-8D1E-48C2D6F81535@gmail.com> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_112_8601933.1390000241866" X-Trace: ger.gmane.org 1390000238 27575 80.91.229.3 (17 Jan 2014 23:10:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 17 Jan 2014 23:10:38 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC47RF4IW4GRB47Q42LAKGQESKMNT3I@isocpp.org Sat Jan 18 00:10:45 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oa0-f72.google.com ([209.85.219.72]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1W4IYm-000190-V5 for gclcip-std-proposals@m.gmane.org; Sat, 18 Jan 2014 00:10:45 +0100 Original-Received: by mail-oa0-f72.google.com with SMTP id o6sf17520434oag.7 for ; Fri, 17 Jan 2014 15:10:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=qp8wQqaNxhMwP57cizMU6I8O0kxBhGJmkXdj5rr7GGI=; b=0ekCJ3rgll8GUe4tJA6/c9DpBaVb0VYtvGS8uO47EXh30QHiLRovf54FlVDQaJUoia 31hKEFgu7JUTKED5Zic4DP02WH+sSs6NSxY9R0AtAGTiqP5dttGTYqDwwRSxms6Yw9dK QrjUcJYbTWAgocTTr2pE3eOjSLTIotpYkLsI/JuG5VOjWfYJY+0zWNUEZF26UPvmfhm0 6a7kdprMyybYP5R8PURchZ3EgX73i1mpZUWwfFYl/1Wg0q1a8MXMufYCiKDnk+LpTEAw EuSwPZ+NTy+Ku95pReTM5V7vIXJot7hHHM0HVS2oKoTbtUQpD2jIJz26ZWlvuNL6Jg+S UAIg== 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:x-original-sender:reply-to:precedence :mailing-list:list-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=qp8wQqaNxhMwP57cizMU6I8O0kxBhGJmkXdj5rr7GGI=; b=GnSah8gFnAw/CNIc/hy02bZsF2Orq6cIKHeWA5/eGm0z7jDQsaWAjpJ4PZ7vJkpcYn PgXx8lMV/gvzKOLiV652eGxyUqCWtNbVeOtkUWCjloE8cleGakEsxpcvhIYAOMFiMcMY Cx2UKwvkkcqC9nnUuKkt+EIH4emhIZBxXw7cGORC2eY7or5JUXYB/9uiM+2WTI3Yzhen Tf7jR7D9OvPmuS/VtaSJRB+m2POmA2+LOrVnGT5YO5NPZksTXCYetWF1nWukl+2tUvS2 XKuKK7ZCKqU8YhIMkRKXJVQAkSJwRYK39DwSwhEONbXx548BJPYGwbCQuGGLvIvLHtJ0 pkrA== X-Gm-Message-State: ALoCoQmBzmVdAaA8Cr9mfqS4XMyY24wElYNE38cylGobNWjGGAeVv5JtPgEqVZmkLAnyQy8BilWp X-Received: by 10.50.124.9 with SMTP id me9mr434281igb.4.1390000243938; Fri, 17 Jan 2014 15:10:43 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.50.176.193 with SMTP id ck1ls695179igc.22.gmail; Fri, 17 Jan 2014 15:10:43 -0800 (PST) X-Received: by 10.50.13.7 with SMTP id d7mr18879igc.16.1390000243179; Fri, 17 Jan 2014 15:10:43 -0800 (PST) In-Reply-To: X-Original-Sender: gornishanov@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:8665 Archived-At: ------=_Part_112_8601933.1390000241866 Content-Type: text/plain; charset=UTF-8 What if string_view provides a specialization for optional>? That way optional can be implemented very efficiently by checking if sv.begin() == nullptr and does not consume any extra storage. An extra benefit is that we have clear distinction between nullable types (optional) and regular types, int, vector, string_view, etc. Will this solution satisfy the original poster? > > -- --- 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_112_8601933.1390000241866 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
What if string_view provides a specialization for opt= ional<string_view<>>?

That way optiona= l<string_view> can be implemented very efficiently by checking if sv.= begin() =3D=3D nullptr and does not consume any extra storage. An extra ben= efit is that we have clear distinction between nullable types (optional<= T>) and regular types, int, vector, string_view, etc.

Will this solution satisfy the original poster?

--
 
---
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-proposals/<= /a>.
------=_Part_112_8601933.1390000241866-- .