From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10867 invoked by alias); 13 Oct 2016 15:15:20 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 10834 invoked by uid 89); 13 Oct 2016 15:15:19 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,SPF_PASS autolearn=no version=3.3.2 spammy= X-HELO: gproxy1.mail.unifiedlayer.com Received: from gproxy1-pub.mail.unifiedlayer.com (HELO gproxy1.mail.unifiedlayer.com) (69.89.25.95) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 13 Oct 2016 15:15:09 +0000 Received: from cmgw2 (cmgw3 [10.0.90.83]) by gproxy1.mail.unifiedlayer.com (Postfix) with ESMTP id 37BD8175E62 for ; Thu, 13 Oct 2016 08:51:24 -0600 (MDT) Received: from box522.bluehost.com ([74.220.219.122]) by cmgw2 with id v2rK1t0022f2jeq012rNQA; Thu, 13 Oct 2016 08:51:22 -0600 X-Authority-Analysis: v=2.1 cv=PIacp5aC c=1 sm=1 tr=0 a=GsOEXm/OWkKvwdLVJsfwcA==:117 a=GsOEXm/OWkKvwdLVJsfwcA==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=CH0kA5CcgfcA:10 a=20KFwNOVAAAA:8 a=qoVMhd0dB6rOsfoIrL8A:9 a=e_O65bzb51kRm2y5VmPK:22 Received: from 174-16-143-211.hlrn.qwest.net ([174.16.143.211]:39248 helo=pokyo) by box522.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86_1) (envelope-from ) id 1buhLs-00037O-BS; Thu, 13 Oct 2016 08:51:20 -0600 From: Tom Tromey To: Pedro Alves Cc: Tom Tromey , gdb-patches@sourceware.org Subject: Re: [RFA 14/22] Replace two xmallocs with vector References: <1474949330-4307-1-git-send-email-tom@tromey.com> <1474949330-4307-15-git-send-email-tom@tromey.com> <2bb436df-b6ee-cc2f-c4c1-1a79d6fcdce1@redhat.com> Date: Thu, 13 Oct 2016 15:15:00 -0000 In-Reply-To: <2bb436df-b6ee-cc2f-c4c1-1a79d6fcdce1@redhat.com> (Pedro Alves's message of "Sun, 9 Oct 2016 18:20:36 +0100") Message-ID: <87oa2oxpy6.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-BWhitelist: no X-Exim-ID: 1buhLs-00037O-BS X-Source-Sender: 174-16-143-211.hlrn.qwest.net (pokyo) [174.16.143.211]:39248 X-Source-Auth: tom+tromey.com X-Email-Count: 2 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTIyLmJsdWVob3N0LmNvbQ== X-SW-Source: 2016-10/txt/msg00376.txt.bz2 >>>>> "Pedro" == Pedro Alves writes: Pedro> As general guideline, for these cases where we only need to Pedro> construct a buffer once (never resize/reallocate) and we don't Pedro> care about the initial contents of the buffer, I think Pedro> unique_ptr buf (new char[size]); Pedro> ends up being more efficient, because std::vector Pedro> default/zero initializes its elements, which is unnecessary since Pedro> we're about to write into the buffer anyway. I made this change in my patches. While doing so I realized one reason to prefer vector: with vector you can build gdb with the libstdc++ debug mode, and get range checking. Tom