From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66579C02198 for ; Mon, 10 Feb 2025 14:12:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1thUWf-0007Fz-8s; Mon, 10 Feb 2025 09:12:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1thUWS-0007Dk-9j; Mon, 10 Feb 2025 09:12:33 -0500 Received: from mgamail.intel.com ([198.175.65.9]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1thUWP-00053L-Pz; Mon, 10 Feb 2025 09:12:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1739196746; x=1770732746; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=8bZA4Uzy6BHrko0L1T3EoFFplZmi9GTEN8JhOqR3zYU=; b=e82qb/KmSuXkrrBlW+yFUG+LRt27XPGz6dNqZ00hv7g0hJGANxdqTbCV 2jvaQ5qYihs9Dolr7OWEUU4SbZl74sb8Mxy8e0Sm4fdB0JLaPyRQwbfF6 3sF1kBzD+cDNaLMvCnjpca1emNLtjJT1TENdrzHeJUHlxN5GDnCE60sPg +kLWgcKkZfNWqEniaKQrva9GryeBPDia9K8DtT7XmV3WryeQtYq/t7E+t /5it2wK8nphIXm1UkVsG8QvU3rRSP0WFnC9qm4NfBARIqovW42n1Izm8Y Wyj7YSeVSrodL1SvYJCF6+VfOohhUA76z+qJLuGBA58zDRsookRmkk48v A==; X-CSE-ConnectionGUID: jvV2+jdOTTebMX9VSx2R8A== X-CSE-MsgGUID: INcyIQrMShunGQyw0h3TZg== X-IronPort-AV: E=McAfee;i="6700,10204,11341"; a="62252958" X-IronPort-AV: E=Sophos;i="6.13,274,1732608000"; d="scan'208";a="62252958" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2025 06:12:23 -0800 X-CSE-ConnectionGUID: IlnqHOzYRIu5mZ+/IPaQ8A== X-CSE-MsgGUID: KXqy4DV0Ri+lLXY1XEY54Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,274,1732608000"; d="scan'208";a="112039099" Received: from liuzhao-optiplex-7080.sh.intel.com (HELO localhost) ([10.239.160.39]) by fmviesa006.fm.intel.com with ESMTP; 10 Feb 2025 06:12:21 -0800 Date: Mon, 10 Feb 2025 22:31:52 +0800 From: Zhao Liu To: Paolo Bonzini Cc: qemu-devel@nongnu.org, qemu-rust@nongnu.org Subject: Re: [PATCH 03/12] rust: callbacks: allow passing optional callbacks as () Message-ID: References: <20250207101623.2443552-1-pbonzini@redhat.com> <20250207101623.2443552-4-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250207101623.2443552-4-pbonzini@redhat.com> Received-SPF: pass client-ip=198.175.65.9; envelope-from=zhao1.liu@intel.com; helo=mgamail.intel.com X-Spam_score_int: -57 X-Spam_score: -5.8 X-Spam_bar: ----- X-Spam_report: (-5.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.388, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Feb 07, 2025 at 11:16:14AM +0100, Paolo Bonzini wrote: > Date: Fri, 7 Feb 2025 11:16:14 +0100 > From: Paolo Bonzini > Subject: [PATCH 03/12] rust: callbacks: allow passing optional callbacks as > () > X-Mailer: git-send-email 2.48.1 > > In some cases, callbacks are optional. Using "Some(function)" and "None" > does not work well, because when someone writes "None" the compiler does > not know what to use for "F" in "Option". > > Therefore, adopt () to mean a "null" callback. It is possible to enforce > that a callback is valid by adding a "let _: () = F::ASSERT_IS_SOME" before > the invocation of F::call. > > Signed-off-by: Paolo Bonzini > --- > rust/qemu-api/src/callbacks.rs | 97 ++++++++++++++++++++++++++++++++++ > 1 file changed, 97 insertions(+) > Reviewed-by: Zhao Liu