From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by olra.theworths.org (Postfix) with ESMTP id 52619429E32 for ; Wed, 23 Oct 2013 17:05:52 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at olra.theworths.org X-Spam-Flag: NO X-Spam-Score: 0 X-Spam-Level: X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] autolearn=disabled Received: from olra.theworths.org ([127.0.0.1]) by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Gtioy34PkaA2 for ; Wed, 23 Oct 2013 17:05:46 -0700 (PDT) Received: from yantan.tethera.net (yantan.tethera.net [199.188.72.155]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by olra.theworths.org (Postfix) with ESMTPS id C5597429E29 for ; Wed, 23 Oct 2013 17:05:46 -0700 (PDT) Received: from remotemail by yantan.tethera.net with local (Exim 4.80) (envelope-from ) id 1VZ8Qj-0000Ea-2P; Wed, 23 Oct 2013 21:05:37 -0300 Received: (nullmailer pid 3578 invoked by uid 1000); Thu, 24 Oct 2013 00:05:33 -0000 From: David Bremner To: Austin Clements , Tomi Ollila Subject: Re: [PATCH 1/3] cli: add insert --must-index option In-Reply-To: <20131023193209.GF20337@mit.edu> References: <1374365254-13227-1-git-send-email-novalazy@gmail.com> <87ip048gbj.fsf@qmul.ac.uk> <20130727151510.GA13750@hili.localdomain> <87hadtxfrr.fsf@qmul.ac.uk> <20130912001349.GA18821@hili.localdomain> <87zjqhv264.fsf@zancas.localnet> <87bo2xtdp2.fsf@unb.ca> <20131023193209.GF20337@mit.edu> User-Agent: Notmuch/0.16+97~g6878b0b (http://notmuchmail.org) Emacs/24.3.1 (x86_64-pc-linux-gnu) Date: Wed, 23 Oct 2013 21:05:33 -0300 Message-ID: <87ob6fv8he.fsf@zancas.localnet> MIME-Version: 1.0 Content-Type: text/plain Cc: notmuch@notmuchmail.org X-BeenThere: notmuch@notmuchmail.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Use and development of the notmuch mail system." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Oct 2013 00:05:52 -0000 Austin Clements writes: > And in libnotmuch, we would do something like > > notmuch_status_t > notmuch_database_open (const char *path, > notmuch_database_mode_t mode, > const notmuch_options_t *options, > notmuch_database_t **database) > { > notmuch_option_t real_options = NOTMUCH_OPTIONS_INIT; > if (real_options.options_length < options.options_length) > return error; > memmove(&real_options, options, options.options_length); > // ... > } > Does the C standard guarantee that if two structs have the same initial set of members, that they are aligned in a compatible way? I suppose it must work, but I'm still curious. Yet another approach would be to pass in array of descriptors, something like the command line argument parsing code does now. libnotmuch_opt_desc_t options[] = { { LIBNOTMUCH_OPT_LOGHOOK, loghook }, { 0, 0} } I guess passing a (void *) as the second element of the pair? Of course it's a bit more work to unpack this way.