From patchwork Thu Aug 26 23:13:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Wakely X-Patchwork-Id: 1521432 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.a=rsa-sha256 header.s=default header.b=H5Qtl1pu; dkim-atps=neutral Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Gwdxf0v43z9sVw for ; Fri, 27 Aug 2021 09:15:48 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 4442E385841C for ; Thu, 26 Aug 2021 23:15:46 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4442E385841C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1630019746; bh=lpyMLuylDrHv6HPSoxwf9trgBMbqHpv75+G+5DSdFsQ=; h=Date:To:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=H5Qtl1puijx/NPu3dw4zLYjhJ9HycTJ/5svsevh/UTz6vUa8p5Kfu6bTD8zQ4fK6H mzFw6Aecc8VKFrptRw6TY2Sto8BEylBaZT7N+f+tmpr0zY8lJKQWuDSK9YIea/5Ym7 qFJl2CNW+HoivBoQ+t9c8/OvClI5uumtSf4wSf7A= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTP id BBC00385841A for ; Thu, 26 Aug 2021 23:13:16 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BBC00385841A Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-460-7O6L1796NCOBF4I-FHAAjQ-1; Thu, 26 Aug 2021 19:13:12 -0400 X-MC-Unique: 7O6L1796NCOBF4I-FHAAjQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E829C1008062; Thu, 26 Aug 2021 23:13:11 +0000 (UTC) Received: from localhost (unknown [10.33.36.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8F63E1002F12; Thu, 26 Aug 2021 23:13:11 +0000 (UTC) Date: Fri, 27 Aug 2021 00:13:10 +0100 To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Add static assertions for std::function requirements Message-ID: MIME-Version: 1.0 X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-Spam-Status: No, score=-14.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP 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: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Jonathan Wakely via Gcc-patches From: Jonathan Wakely Reply-To: Jonathan Wakely Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" Add static assertions to std::function, so that more user-friendly diagnostics are given when trying to store a non-copyable target object. These preconditions were added as "Mandates:" by LWG 2447, but I'm committing them separately from implementing that, to allow just this change to be backported more easily. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/std_function.h (function::function(F)): Add static assertions to check constructibility requirements. Tested powerpc64le-linux. Committed to trunk. commit 8cf428bfd3ca967b3d135e311d3e391998a39335 Author: Jonathan Wakely Date: Thu Aug 26 13:13:27 2021 libstdc++: Add static assertions for std::function requirements Add static assertions to std::function, so that more user-friendly diagnostics are given when trying to store a non-copyable target object. These preconditions were added as "Mandates:" by LWG 2447, but I'm committing them separately from implementing that, to allow just this change to be backported more easily. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/std_function.h (function::function(F)): Add static assertions to check constructibility requirements. diff --git a/libstdc++-v3/include/bits/std_function.h b/libstdc++-v3/include/bits/std_function.h index fb86ff1c5f8..e081cd81ef4 100644 --- a/libstdc++-v3/include/bits/std_function.h +++ b/libstdc++-v3/include/bits/std_function.h @@ -422,6 +422,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION function(_Functor __f) : _Function_base() { + static_assert(is_copy_constructible<_Functor>::value, + "std::function target must be copy-constructible"); + static_assert(is_constructible<_Functor, _Functor>::value, + "std::function target must be constructible from the " + "constructor argument"); + using _My_handler = _Function_handler<_Res(_ArgTypes...), _Functor>; if (_My_handler::_M_not_empty_function(__f))