From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id F07443858C00 for ; Mon, 26 Sep 2022 16:02:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org F07443858C00 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664208168; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JmM1Oibhj6j5vjDduge5+zd/X5i50n1BcsSKUXJKOJ4=; b=SS2MVFAmpHfbokPjh3ZU7njA6JUbufLb0QUi1Dww78pnuN1yjwYc1q0SSSZ/wtwairYwXS AxnKv2idmNZeTLGN4i/zTrXt8dX/rmjDvVmk+h1iR1Eo1yKjMkE5nrKoL5qfwQbJlNdmNG gbTIn2rRGNSnc1Zy7uTNnNFvrbgjnNw= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-348-Ct80woyqP76_pW5_yOeb9Q-1; Mon, 26 Sep 2022 12:02:47 -0400 X-MC-Unique: Ct80woyqP76_pW5_yOeb9Q-1 Received: by mail-qv1-f69.google.com with SMTP id nn9-20020a056214358900b004ac7136c9a3so4072403qvb.16 for ; Mon, 26 Sep 2022 09:02:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=JmM1Oibhj6j5vjDduge5+zd/X5i50n1BcsSKUXJKOJ4=; b=jYCKk3b4eUYkswb6MV/Rj1Oplm0Sm+pUNeXrvtIKFUAZxPZmuChqbWTJsgWtE77h64 NIVT6JQIA1SZzHnwelrst5jH6xQep1F/K/9r3ctLPEAEF4wrFBwb4qdEtpuDGuj8/Mqu S5cY69Z1zrVb8YrKX7XXxS868jCXl8TRKOwfArMD4TlV4Gz5BpQ9uPgy0Han3EWGqhOB RIDIKHARyZ2hrXJ9ZsMyX1byGlfE9elVgBwgD/wTICC0LvGSsRXtrHnd0dfQT2Z99N8o mB0Lt2g5SjOF3FpsK5Y0UmC4LIICiPULn60xZWIXiwk8OrOVROCJYoEn72kUTbYDFycD pq6g== X-Gm-Message-State: ACrzQf1rs8TAtEUueGYdBV/WGrpau12gjdKM02/QsaS3TjofjFXZZMax 87fhjUH9Q1x90G4Lbn8q1caXgGDafAcUF2bapAw28kDkEL3/7EUSXSMqACl0EEYumrfnO++sGBL 1g7G26qes423y7dWYS9auJYH2zZPJ6o9b4g== X-Received: by 2002:a05:6214:1d2c:b0:4af:7b02:ab28 with SMTP id f12-20020a0562141d2c00b004af7b02ab28mr2019534qvd.41.1664208167198; Mon, 26 Sep 2022 09:02:47 -0700 (PDT) X-Google-Smtp-Source: AMsMyM71wULULsXcJPgItJMExsEO3N/th99O4HPJcly2/Z/gxHqRWQtXTh7z4CHUtyCU3h/wTgZ8QFiBASdFa/ujl8c= X-Received: by 2002:a05:6214:1d2c:b0:4af:7b02:ab28 with SMTP id f12-20020a0562141d2c00b004af7b02ab28mr2019504qvd.41.1664208167002; Mon, 26 Sep 2022 09:02:47 -0700 (PDT) MIME-Version: 1.0 References: <20220926152258.20921-1-polacek@redhat.com> In-Reply-To: <20220926152258.20921-1-polacek@redhat.com> From: Jonathan Wakely Date: Mon, 26 Sep 2022 17:02:36 +0100 Message-ID: Subject: Re: [PATCH] c++: Instantiate less when evaluating __is_convertible To: Marek Polacek Cc: GCC Patches , Jason Merrill X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-6.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Mon, 26 Sept 2022 at 16:23, Marek Polacek wrote: > > Jon reported that evaluating __is_convertible in this test leads to > instantiating char_traits::eq, which is invalid (because we > are trying to call a member function on a char) N.B. in the original code wasn't trying to do something dumb like call a member function on a char, but it was using basic_string_view where X is a class type without an operator== and so char_traits::eq was invalid. I changed it to just use basic_string_view and changed char_traits::eq to do something different, that was invalid for char. I can provide a less silly test case if you like, but I don't think it matters for the purposes of the testsuite.