220 10427 article Path: news.gmane.org!not-for-mail From: Andrew Tomazos Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Generated initializer_list Date: Tue, 29 Apr 2014 14:56:07 +0200 Lines: 42 Approved: news@gmane.org Message-ID: References: <357dd72f-c749-4dc5-aa6d-5ac4528aba5a@isocpp.org> <2be92780-bf68-4634-a193-7461f71de3f7@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: ger.gmane.org 1398776177 26718 80.91.229.3 (29 Apr 2014 12:56:17 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 29 Apr 2014 12:56:17 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBD5KHQXXWYPRB2GC72NAKGQE44EX6QQ@isocpp.org Tue Apr 29 14:56:10 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wg0-f69.google.com ([74.125.82.69]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Wf7Zy-0006sR-4s for gclcip-std-proposals@m.gmane.org; Tue, 29 Apr 2014 14:56:10 +0200 Original-Received: by mail-wg0-f69.google.com with SMTP id k14sf99666wgh.4 for ; Tue, 29 Apr 2014 05:56:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe:content-type; bh=zZPpXmw36ODMz6vyMtLP+1AYNQ9vnS8dTeRzoyq15nc=; b=GL8SMw95p3qOKt+QVO+pwNMaNfo5s2TvVVw7AJsPq5/kK9V4lTir2hIlPuLBhHff7E H6y1uespmAOPOsgLBet2tTnZZ1vawnLuvu42IhKsp2Rn96v/QNic0gyrXKQ8TcuBmaVZ WgqbpxTqKYO8DWaYszHHt1kn1LUyR+hXhft3dfXdpmYJIM/eeieqwOUIAj4/I4jJlFwm n1KiqR5i8YrCr66ZwfwcktIXbNRJ3ZFPcr2ebDrgzchOOq9NpinEd+VDpRamPeyeqNXq z5KZLAjVB+eDvODXNWmC+NkhAL5q2uRwjbeyQEHZAjRsyD3SS5Gv5lrUDciM7F3fvMvp B75w== X-Gm-Message-State: ALoCoQnbss/zxpXYASl181ptUP3dGn95E1LjwhJTOII+8tYhfEgSHgUhvJdGVAXaLlJcnuKNXUWJ X-Received: by 10.152.3.38 with SMTP id 6mr2718146laz.0.1398776169614; Tue, 29 Apr 2014 05:56:09 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.91.116 with SMTP id cd20ls62232wib.18.gmail; Tue, 29 Apr 2014 05:56:08 -0700 (PDT) X-Received: by 10.194.118.163 with SMTP id kn3mr1053931wjb.77.1398776168312; Tue, 29 Apr 2014 05:56:08 -0700 (PDT) Original-Received: from mail-wg0-x234.google.com (mail-wg0-x234.google.com [2a00:1450:400c:c00::234]) by mx.google.com with ESMTPS id bo8si8186577wjb.27.2014.04.29.05.56.08 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 29 Apr 2014 05:56:08 -0700 (PDT) Received-SPF: pass (google.com: domain of andrewtomazos@gmail.com designates 2a00:1450:400c:c00::234 as permitted sender) client-ip=2a00:1450:400c:c00::234; Original-Received: by mail-wg0-f52.google.com with SMTP id l18so168580wgh.35 for ; Tue, 29 Apr 2014 05:56:08 -0700 (PDT) X-Received: by 10.194.1.242 with SMTP id 18mr24659959wjp.22.1398776167895; Tue, 29 Apr 2014 05:56:07 -0700 (PDT) Original-Received: by 10.227.203.71 with HTTP; Tue, 29 Apr 2014 05:56:07 -0700 (PDT) In-Reply-To: <2be92780-bf68-4634-a193-7461f71de3f7@isocpp.org> X-Original-Sender: andrewtomazos@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of andrewtomazos@gmail.com designates 2a00:1450:400c:c00::234 as permitted sender) smtp.mail=andrewtomazos@gmail.com; dkim=pass header.i=@gmail.com; dmarc=pass (p=NONE dis=NONE) header.from=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:10427 Archived-At: > I would like to type something along the lines of: > > constexpr auto primes[5] = get_nth_prime; > > given a function > > constexpr unsigned int get_nth_prime(size_t n) > > which would be equivalent to > > constexpr unsigned int primes[] = {2, 3, 5, 7, 11}; Let us ignore prime sieves for the moment, and assume you have an expensive function get_nth_prime. You can write the following I think: constexpr std::array cache_primes() { std::array A = {0}; for (size_t i = 0; i < 5; i++) A[i] = get_nth_primes(i); return A; } constexpr std:array primes = cache_primes(); cache_primes is called during translation (at compile-time), the primes array is filed out and (assuming odr-used) is stored in the object file like you want. Is that what you mean? -- --- 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/. .