From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id ehE6MsIQil/XdQAAWB0awg (envelope-from ) for ; Fri, 16 Oct 2020 17:29:38 -0400 Received: by simark.ca (Postfix, from userid 112) id C03E51EF6F; Fri, 16 Oct 2020 17:29:38 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,T_DKIM_INVALID,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 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 (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 5FB8F1E58E for ; Fri, 16 Oct 2020 17:29:38 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D3FBE3857839; Fri, 16 Oct 2020 20:51:15 +0000 (GMT) Received: from gateway20.websitewelcome.com (gateway20.websitewelcome.com [192.185.60.19]) by sourceware.org (Postfix) with ESMTPS id AD2033857839 for ; Fri, 16 Oct 2020 20:51:13 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org AD2033857839 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=tom@tromey.com Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 407BB400DA57B for ; Fri, 16 Oct 2020 15:49:42 -0500 (CDT) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id TWgzkg7vDOIGpTWgzkoMqa; Fri, 16 Oct 2020 15:51:13 -0500 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=8R3Z7KlQGnVH00zVPPw2yFQyfSLNFaULcRSgPD8F60c=; b=dtqwlluNRhlbUtV5uIOu1nTEAr VSC6qVq+VhnLZJXfj/O4gcPiGOmOgrh3h76285bdAq+Mme9qqgQ/6KIDFSa9W1MJbbxLuVbCgxtGv bHq4YwskgecuO3c35uSm0+7G+; Received: from 75-166-102-113.hlrn.qwest.net ([75.166.102.113]:44606 helo=murgatroyd) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kTWgy-002uj6-R3; Fri, 16 Oct 2020 14:51:12 -0600 From: Tom Tromey To: Pedro Alves Subject: Re: [PATCH v2] gdb::handle_eintr, remove need to specify return type References: <20200904002905.13616-1-n54@gmx.com> <20200904002905.13616-2-n54@gmx.com> <75070000-03a2-eeed-4f72-e29f199291af@palves.net> <223cf7ec-36b5-fe52-7d0f-e19c335be534@palves.net> X-Attribution: Tom Date: Fri, 16 Oct 2020 14:51:10 -0600 In-Reply-To: <223cf7ec-36b5-fe52-7d0f-e19c335be534@palves.net> (Pedro Alves's message of "Tue, 13 Oct 2020 15:17:00 +0100") Message-ID: <87a6wlopxd.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 75.166.102.113 X-Source-L: No X-Exim-ID: 1kTWgy-002uj6-R3 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 75-166-102-113.hlrn.qwest.net (murgatroyd) [75.166.102.113]:44606 X-Source-Auth: tom+tromey.com X-Email-Count: 6 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Simon Marchi , Kamil Rytarowski , tom@tromey.com, gdb-patches@sourceware.org Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" >>>>> "Pedro" == Pedro Alves writes: Pedro> This eliminates the need to specify the return type when using Pedro> handle_eintr. We let the compiler deduce it for us. Thanks for doing this. This is closer to how I imagined this wrapper being written. Pedro> +template + typename Fun, Pedro> + typename... Args> Pedro> +inline auto Pedro> +handle_eintr (ErrorValType errval, const Fun &f, const Args &... args) Pedro> + -> decltype (f(args...)) It seems to me that errval and ErrorValType are unchanging properties of the function being wrapped. And, normally they are -1 / int. Also is there ever a case where the return type isn't the same as ErrorValType? So maybe instead of requiring these to all be redundantly specified, the template could use a helper template class that specifies these things (defaulting to the usual), and then one would write: pid_t pid = gdb::handle_eintr<::waitpid> (...normal waitpid args); I'm not sure it's really worth implementing this, but it's closer to what I was picturing initially. Tom