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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 2CA2D3858C20 for ; Fri, 11 Feb 2022 13:35:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2CA2D3858C20 Received: from mail-yb1-f199.google.com (mail-yb1-f199.google.com [209.85.219.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-189-jaRtHl-kPAqXOdEIckr8Nw-1; Fri, 11 Feb 2022 08:35:34 -0500 X-MC-Unique: jaRtHl-kPAqXOdEIckr8Nw-1 Received: by mail-yb1-f199.google.com with SMTP id a32-20020a25ae20000000b0061db8f89e46so18691193ybj.14 for ; Fri, 11 Feb 2022 05:35:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RlJ/kgxGdK5Ly50ey+geja7gSug977Dzbhha9RomISQ=; b=eAeZcv34jsGcxCu2/XjXHqsYFZnI+oD7vogKizySmimbz0WWIRqq0zrYHWxImpGzcw 9J6+nKD/YwDQ3NNcI53MjwJb3Ycvgcx+GxLmUTU811Oe9yXvxT7aXFsOjKg1/23UVIzk r8uURNtLAY6nCDU3KfcDEgS2SKFrHRzJ4fXUQUq7YVNDmoN2Od6qoTpfOYdNkmYAh2xK 9I2NlRRUycyE2/+EN0VX/5m6AgwDKtyMCYnxz/nW51L5IUTJqcX9kdNMVcIQe236PsYb HmBicqmrNTol07lh3kHkuodC6URluQEShk+yDmUmMsUFtkVc3zTsRxBIFC217H/hkJLW WVhw== X-Gm-Message-State: AOAM532Q0Fcf5TufWjy3bzAwEt66/fu463X7Wol9g7mQrJZ71nFofEP0 XNCxaXEMEeoZRVH+aM3sT3Kay30HALhxIp0kk295BbJHt1GuebITGhk96MaiCgkDN7S1pMY78Mi gfugoxDpFbSJ5SznKMsLVDfgen8UxkAs= X-Received: by 2002:a25:e64e:: with SMTP id d75mr1383766ybh.253.1644586533604; Fri, 11 Feb 2022 05:35:33 -0800 (PST) X-Google-Smtp-Source: ABdhPJwTOhCIft13N95+A696vFvoxEThjy2waYC0HnkrkfYR9wh3cuxqfLjX88yA/tFpnLNAin7d4dr4Mjp/7xomGr8= X-Received: by 2002:a25:e64e:: with SMTP id d75mr1383743ybh.253.1644586533418; Fri, 11 Feb 2022 05:35:33 -0800 (PST) MIME-Version: 1.0 References: <20220210165624.2953676-1-ppalka@redhat.com> <76be2843-238f-ffd9-c638-3a53d7c85a7e@idea> In-Reply-To: <76be2843-238f-ffd9-c638-3a53d7c85a7e@idea> From: Jonathan Wakely Date: Fri, 11 Feb 2022 13:35:22 +0000 Message-ID: Subject: Re: [PATCH 1/3, 11 backport] libstdc++: Implement P2325 changes to default-constructibility of views To: Patrick Palka Cc: "libstdc++" , gcc Patches X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Feb 2022 13:35:37 -0000 On Thu, 10 Feb 2022 at 17:29, Patrick Palka via Libstdc++ wrote: > > On Thu, 10 Feb 2022, Patrick Palka wrote: > > > Tested on x86_64-pc-linux-gnu, does this look OK for the 11 branch? > > The backport to the 10 branch hasn't been started yet, I figured it'd > > be good to first get the 11 backport right then base the 10 backport > > on the 11 one. > > > > NB: This backport of r12-1606 to the 11 branch deliberately omits parts > > of P2325R3 so as to maximize backward compatibility with pre-P2325R3 code. > > In particular, we don't remove the default ctors for back_insert_iterator, > > front_insert_iterator, ostream_iterator, ref_view and basic_istream_view. [...] > > @@ -670,8 +710,6 @@ namespace views > > using difference_type = ptrdiff_t; > > using value_type = _Val; > > > > - _Iterator() = default; > > Drat, this default ctor (for basic_istream_view::iterator) should not > be removed in the backport. Here's v2 which fixes this mistake (and > thus the static_assert on line 77 of p2325.cc now fails as expected): Good catch. This one's OK for gcc-11, and if it applies cleanly to gcc-10 as-is, there too.