From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22351 invoked by alias); 7 Jun 2015 08:50:26 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 22326 invoked by uid 89); 7 Jun 2015 08:50:25 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 X-Spam-User: qpsmtpd, 2 recipients X-HELO: mail2-relais-roc.national.inria.fr Received: from mail2-relais-roc.national.inria.fr (HELO mail2-relais-roc.national.inria.fr) (192.134.164.83) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (CAMELLIA256-SHA encrypted) ESMTPS; Sun, 07 Jun 2015 08:50:24 +0000 Received: from ip-111.net-81-220-140.rev.numericable.fr (HELO laptop-mg.local) ([81.220.140.111]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-SHA; 07 Jun 2015 10:50:20 +0200 Date: Sun, 07 Jun 2015 11:37:00 -0000 From: Marc Glisse Reply-To: libstdc++@gcc.gnu.org To: Ville Voutilainen cc: libstdc++@gcc.gnu.org, "gcc-patches@gcc.gnu.org" Subject: Re: [v3 PATCH] Implement N4387 and LWG 2367 In-Reply-To: Message-ID: References: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII X-SW-Source: 2015-06/txt/msg00512.txt.bz2 On Sun, 7 Jun 2015, Ville Voutilainen wrote: > On 7 June 2015 at 11:12, Ville Voutilainen wrote: >>> Does the following code still compile with your patch? >>> struct A { int a,b; }; >>> std::tuple a(3,4,{1,2}); >> >> No. :/ And we have no test for it.. I'll need to look at that. > > Ahem, yes, this is because the constructor that used to take _Elements > now takes _UElements. I can change it back to take _Elements, because > the technique that the default constructors use allow making the signature > dependent enough that it will sfinae correctly. Yes. >>> You use a lot: typename enable_if::type=true >>> while the current code seems to favor: class=typename enable_if::type. >>> I don't really care which one is used, but it is easier to read when the >>> style is consistent through the library. >> It's not a style issue. That template parameter needs to be a non-type one, >> otherwise the overloads are ambiguous. Ah, I had overlooked that. I have seen several work-arounds for this issue, but I don't remember this one, it seems nice. -- Marc Glisse