From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 116919 invoked by alias); 4 Aug 2017 18:06:07 -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 115863 invoked by uid 89); 4 Aug 2017 18:06:06 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,SPF_PASS autolearn=no version=3.3.2 spammy=Hx-languages-length:1042 X-HELO: mail-io0-f173.google.com Received: from mail-io0-f173.google.com (HELO mail-io0-f173.google.com) (209.85.223.173) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 04 Aug 2017 18:06:05 +0000 Received: by mail-io0-f173.google.com with SMTP id g35so8567371ioi.3 for ; Fri, 04 Aug 2017 11:06:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=z0ob+moLpjjz1lMDQfYW5FLrE5NzCga/tIQuSq9SToo=; b=a/taaOJq5LBtmzoWkyHcJIzFCGU5hl6+A+R8lTXNdvJNv9CkPcnGuTSFboLqSYg33r dEL1ycTG2WNSv546+3asmqsiqmw12VYF7g5dtpXUwD50rvlNKfQRf/jDa6pOUhqIDJ2R qCXOl1sCJOayz/8VABJnrYOLsekgm7xeoZtDZ1Uat+VnVCATTM4i0GWsy0LmXxFHh0as /WuZZHDSeVuSRs5/G0JpCBHyF4R/hI451MLG3PMOZV9DCSFDqtP4u3jzTxMEan8ynqRT sjTMyyqYvsH2JNFJflXN3Vse8qmrwm+i+xGRUk2v7G+nv7IC32JlB6KD3faZeIkHdRDn yZSw== X-Gm-Message-State: AHYfb5gggR+50KPZKbVGICuF+IHRGd0hcI4ryqhhAmQtkxaE199zInAF oPckNWDtlE0LVF5fr5PcCHEYDuoIqA== X-Received: by 10.107.17.71 with SMTP id z68mr3260619ioi.266.1501869963721; Fri, 04 Aug 2017 11:06:03 -0700 (PDT) MIME-Version: 1.0 Received: by 10.79.38.84 with HTTP; Fri, 4 Aug 2017 11:05:43 -0700 (PDT) In-Reply-To: References: <25e893cd-0bf5-4c5e-24b7-70daba6793dc@oracle.com> <52faa01e-7b9c-8f25-a7c5-1bc168eab5d1@redhat.com> From: Tim Song Date: Fri, 04 Aug 2017 18:06:00 -0000 Message-ID: Subject: Re: [C++ Patch] PR 79790 ("[C++17] ICE class template argument deduction") To: Paolo Carlini Cc: Jason Merrill , "gcc-patches@gcc.gnu.org" Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes X-SW-Source: 2017-08/txt/msg00405.txt.bz2 On Fri, Aug 4, 2017 at 1:32 PM, Paolo Carlini wrote: > About the exact wording, I'm a little puzzled, because, besides the > "implicit" nit, the "copy-inizialization" already occurs in two other places > in that function, in the preceding: > > if (elided && !cands) > { > error ("cannot deduce template arguments for copy-initialization" > " of %qT, as it has no non-explicit deduction guides or " > "user-declared constructors", type); > return error_mark_node; > } > > and in the following: > > if (elided) > inform (input_location, "explicit deduction guides not considered " > "for copy-initialization"); > > and now I'm wondering which, if any, should be also removed?!? Both? Can you > help me about that? > > Thanks, > Paolo. These messages are only emitted when elided == true, which, if I'm reading the code correctly, is only the case when you are in copy-initialization context (and have skipped at least one explicit guide).