From 5124178322338075962 X-Google-Thread: 7894ca11fe,191c67e7ffa6c8e7,start X-Google-Attributes: gid7894ca11fe,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news2.google.com!news.glorb.com!news2.glorb.com!news.alt.net From: Trigve Siver Newsgroups: comp.std.c++ Subject: Re: reinterpret_cast(&some_int) Date: Wed, 13 Oct 2010 11:52:27 CST Organization: unknown Lines: 46 Sender: std-c++-request@ruralroute.cs.rpi.edu Approved: austern@google.com Message-ID: <402768.38178.qm@web110410.mail.gq1.yahoo.com> NNTP-Posting-Host: netlab.cs.rpi.edu Content-Type: text/plain; charset=utf-8 To: (Usenet) Return-Path: X-Hash: SCt|118745335635dafbf704497c7087f53f0f9bd92c|399459334153dc477ce38273af05e388 X-Countries: United States X-SMTP-From: accepted assassin.cs.rpi.edu [128.113.126.17] (assassin.cs.rpi.edu) {United States} DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=cs.rpi.edu; h=date :to:sender:message-id:from:subject:content-type; s=default; i= 128.113.126.17@cs.rpi.edu; t=1286988746; x=1287593546; l=1416; bh=eih4/DEP8z0zZMHF1/c53HjVEfs=; b=mMz/cIfCYK5RksfBNjNF3pyYJtVK I7dUb4sqiUpe5xlIZzT4deGBSgxq6WNMFBefwD7WKl21DpyLhTgkEK1mNAHSpzCZ lawE2+7yDBZGNaL2jTFZdzXIXL5IWBjV6PT/rVwd9JGSgMTY8A9MUC4wxsZhS5SP 4LKZqpq8C1kwEQA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=cs.rpi.edu; h=date:to:sender :message-id:from:subject:content-type; q=dns; s=default; b=CNv5j R6T10r9YhPwGXP2OyHA5EhbN00oVGL3de+Mc9UrzlFwUJvs/AQ4eIN86cTqSY9Dj Ug6PdX/ebzJZUaOwplBRMnvq8axwbB2cnzcnWfRFKfTT8GoJxSOTfLAOU8aDkO/a xz6yn54VQdKfCEf+7vD6W2xEG+uyB6gHKLEwzg= X-Spam-Report: Spam Report from cliffclavin.cs.rpi.edu (SA:3.2.5): -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP 3.4 HEADER_SPAM Bulk email fingerprint (header-based) found 2.3 FORGED_YAHOO_RCVD 'From' yahoo.com does not match 'Received' headers -0.9 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.2 SARE_HEAD_HDR_APPROV Message headers used which identify spam X-Spam-Info: 3.2, local; ALL_TRUSTED,BAYES_00,FORGED_YAHOO_RCVD,HEADER_SPAM, SARE_HEAD_HDR_APPROV X-Spam-Scanned-By: cliffclavin.cs.rpi.edu using SpamAssassin 3.2.5 X-Virus-Scanned-By: cliffclavin.cs.rpi.edu X-Original-Date: Tue, 12 Oct 2010 00:35:44 -0700 (PDT) X-Submission-Address: std-c++@netlab.cs.rpi.edu X-Scanned-By: MIMEDefang 2.67 on 128.113.126.25 Xref: g2news2.google.com comp.std.c++:3045 On 12. Okt, 02:06 h., James Kanze wrote: > > It is and it isn't. About all you can say is that you're more > or less guaranted to pass the address of the int into > input.read. Since this function expects the address of a char > buffer, and will write it as such, just about anything can > happen after that. Is there ANY portable way to read binary data of PODs from file? Only method I can think of is using "char *" buffer and then "std::memcpy()" to target o= f POD type (3.9/2). > > And what about reinterpret_cast(&some_pod)? > > The same. Then what is 5.2.10/7("...When a prvalue v of type =93pointer to T1=94 is converted to the type =93pointer to cv T2=94, the result is static_cast(static_cast(v)) if both T1 and T2 are standard-layout types (3.9) and the alignment requirements of T2 are no stricter than those of T1....") good for? Could someone give some practical example where the sentence above could be applied and give some defined behaviour but without the sentence above it wouldn't, please? Thank you Trigve -- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@netlab.cs.rpi.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.comeaucomputing.com/csc/faq.html ]