Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!goblin1!goblin.stu.neva.ru!postnews.google.com!news1.google.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!news.giganews.com.POSTED!not-for-mail
NNTP-Posting-Date: Sun, 03 Apr 2011 19:25:46 -0500
From: Pete Becker <pete@versatilecoding.com>
Organization: Roundhouse Consulting, Ltd.
Newsgroups: comp.lang.c++
Date: Sun, 3 Apr 2011 20:25:47 -0400
Message-ID: <2011040320254756281-pete@versatilecodingcom>
References: <xhnlp.1597$0j7.632@newsfe20.ams2> <c14c937c-5626-43cc-a0a6-06b743038e49@e21g2000yqe.googlegroups.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Transfer-Encoding: 8bit
Subject: Re: Compilers way to implement array allocations
User-Agent: Unison/2.1.4
Lines: 35
X-Usenet-Provider: http://www.giganews.com
X-Trace: sv3-3MK/lRDCVIcsQzDaoUZw3rd0aLZ9/I2135j3WFaWdzqpurVW4sBlu/9Gf+tSUoRCcPb9mOp/5z4BxXI!Rkvnfi0GeZBai2q5O+jy02hzVRGs82JDQosgqEr4MUGwvkQHKgmojKc9dSrJB/QhIeZJxnJu
X-Complaints-To: abuse@giganews.com
X-DMCA-Notifications: http://www.giganews.com/info/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 2210
Xref: x330-a1.tempe.blueboxinc.net comp.lang.c++:3065

On 2011-04-03 13:22:26 -0400, James Kanze said:

> On Apr 3, 6:35 am, Goran <goran.pu...@gmail.com> wrote:
>> On Apr 1, 7:32 pm, "crea" <n...@invalid.com> wrote:
> 
>     [...]
>>> So my question is, that why cant I destroy this automatic
>>> object? How/why does the compiler prevent that?
> 
>> Compiler does not prevent it. For example:
> 
>> void f()
>> {
>> int i; // automatic
>> int* p = &i;
>> delete p; // boom
>> }
> 
>> This code is 100% legal, and compiler will compile it without any
>> complaint. But at runtime, boom!
> 
> The code is not "legal" (for the usual definition of legal).  It
> has undefined behavior.  One possible behavior is that the
> compiler refuse to compile it, or issues an error message.
> Another is that something strange happens at runtime.
> 

And a third is that it will "work just fine". Until it doesn't.

-- 
  Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com) Author of "The 
Standard C++ Library Extensions: a Tutorial and Reference 
(www.petebecker.com/tr1book)