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Groups > comp.lang.c > #16721

Re: Size of an arraylist in bytes

From James Kuyper <jameskuyper@verizon.net>
Newsgroups comp.lang.c
Subject Re: Size of an arraylist in bytes
Date 2012-02-05 09:42 -0500
Organization A noiseless patient Spider
Message-ID <jgm4h3$tle$1@dont-email.me> (permalink)
References (3 earlier) <jgi50h$qp$1@dont-email.me> <jgk7nc$bh4$1@reader1.panix.com> <4F2DB1F2.3@verizon.net> <20120205030849.505@kylheku.com> <jgm389$mjh$1@dont-email.me>

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On 02/05/2012 09:20 AM, Eric Sosman wrote:
> On 2/4/2012 9:19 PM, Kaz Kylheku wrote:
>> On 2012-02-04, James Kuyper<jameskuyper@verizon.net>  wrote:
>>> On 02/04/2012 04:25 PM, Joe keane wrote:
>>> ...
>>>> int g(int x)
>>>> {
>>>>      int a[4][5];
>>>>      int *p;
>>>>      int *q;
>>>>      int j;
>>>>
>>>>      p =&a[0][5];
>>>>  [...]
>>>
>>> Because dereferencing p has undefined behavior, a conforming
>>
>> Says you. There isn't a very convincing case for this in the standard.
> 
>      Perhaps you've overlooked the final sentence of 6.5.6p8:
> 
> 	"If the result points one past the last element of the array
> 	object, it shall not be used as the operand of a unary *
> 	operator that is evaluated."

And, as Keith has pointed out, Annex J.2 is an informative listing of
the circumstances under which behavior is undefined. One of those items
says:

"An array subscript is out of range, even if an object is apparently
accessible with the given subscript (as in the lvalue expression a[1][7]
given the declaration int a[4][5]) (6.5.6)."

While Annex J is only informative, it is consistent with and can be
derived from the normative text of 6.5.6, and makes it clear that it was
intended to be interpreted in this fashions.
-- 
James Kuyper

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Thread

Re: Size of an arraylist in bytes Joe Wright <joewwright@comcast.net> - 2011-11-21 16:25 -0500
  Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2011-11-21 14:03 -0800
    Re: Size of an arraylist in bytes pete <pfiland@mindspring.com> - 2011-11-21 17:45 -0500
      Re: Size of an arraylist in bytes Ark <akhasin@macroexpressions.com> - 2011-11-21 21:19 -0500
        Re: Size of an arraylist in bytes Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-21 22:06 -0500
          Re: Size of an arraylist in bytes Ark <akhasin@macroexpressions.com> - 2011-11-22 03:07 -0500
            Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2011-11-22 06:51 -0500
        Re: an instance of an object (was: Size of an arraylist in bytes) Keith Thompson <kst-u@mib.org> - 2011-11-21 21:54 -0800
        Re: Size of an arraylist in bytes pete <pfiland@mindspring.com> - 2011-11-22 01:49 -0500
          Re: Size of an arraylist in bytes Ark <akhasin@macroexpressions.com> - 2011-11-22 03:17 -0500
            Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2011-11-22 00:48 -0800
            Re: Size of an arraylist in bytes pete <pfiland@mindspring.com> - 2011-11-23 05:16 -0500
          Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2011-11-22 16:49 +0000
        Re: Size of an arraylist in bytes pete <pfiland@mindspring.com> - 2011-11-23 09:30 -0500
  Re: Size of an arraylist in bytes Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-22 00:07 -0800
    Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2011-11-22 00:24 -0800
      Re: Size of an arraylist in bytes Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 05:06 -0800
        Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2012-01-25 12:15 -0800
          Re: Size of an arraylist in bytes Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-31 18:49 -0800
            Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2012-02-01 13:53 -0800
              Re: Size of an arraylist in bytes lawrence.jones@siemens.com - 2012-02-01 18:53 -0500
                Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2012-02-01 20:06 -0800
              Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-01 21:40 -0500
                Re: Size of an arraylist in bytes jgk@panix.com (Joe keane) - 2012-02-02 03:45 +0000
                Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2012-02-01 20:14 -0800
                Re: Size of an arraylist in bytes Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-01 23:14 -0500
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-02 18:38 -0500
                Re: Size of an arraylist in bytes jgk@panix.com (Joe keane) - 2012-02-03 16:32 +0000
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-03 11:57 -0500
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-03 20:07 -0500
                Re: Size of an arraylist in bytes jgk@panix.com (Joe keane) - 2012-02-04 22:35 +0000
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-04 18:43 -0500
                Re: Size of an arraylist in bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-05 01:50 +0000
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-04 21:37 -0500
                Re: Size of an arraylist in bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-05 14:48 +0000
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-05 10:20 -0500
                Re: Size of an arraylist in bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-05 16:25 +0000
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-05 12:06 -0500
                Re: Size of an arraylist in bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-05 19:21 +0000
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-05 15:29 -0500
                Re: Size of an arraylist in bytes Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-08 10:46 -0800
                Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2012-02-05 02:39 +0000
                Re: Size of an arraylist in bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-05 15:17 +0000
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-05 12:06 -0500
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-05 15:06 -0500
                Re: Size of an arraylist in bytes jgk@panix.com (Joe keane) - 2012-02-07 17:35 +0000
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-07 19:51 -0500
                Re: Size of an arraylist in bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-08 01:14 +0000
                Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2012-02-05 02:31 +0000
                Re: Size of an arraylist in bytes Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-03 21:26 -0500
                Re: Size of an arraylist in bytes Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-03 21:31 -0500
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-04 06:57 -0500
                Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2012-02-04 18:32 +0000
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-05 22:51 -0500
                Re: Size of an arraylist in bytes jgk@panix.com (Joe keane) - 2012-02-04 21:25 +0000
                Re: Size of an arraylist in bytes Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-04 17:08 -0500
                Re: Size of an arraylist in bytes Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-08 10:52 -0800
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-04 17:32 -0500
                Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2012-02-05 02:19 +0000
                Re: Size of an arraylist in bytes Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-05 09:20 -0500
                Re: Size of an arraylist in bytes James Kuyper <jameskuyper@verizon.net> - 2012-02-05 09:42 -0500
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-05 16:17 -0500
                Re: Size of an arraylist in bytes Zoltan Kocsi <zoltan@bendor.com.au> - 2012-02-05 17:49 +1100
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-05 16:48 -0500
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-05 16:52 -0500
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-02 01:07 -0500
              Re: Size of an arraylist in bytes lawrence.jones@siemens.com - 2012-02-03 11:29 -0500
                Re: Size of an arraylist in bytes Keith Thompson <kst-u@mib.org> - 2012-02-03 12:42 -0800
                lvalue "potentially" designates an object (was Re: Size of an arraylist in bytes) Kenneth Brody <kenbrody@spamcop.net> - 2012-02-04 12:47 -0500
                Re: lvalue "potentially" designates an object (was Re: Size of an arraylist in bytes) Kaz Kylheku <kaz@kylheku.com> - 2012-02-04 18:39 +0000
                Re: Size of an arraylist in bytes lawrence.jones@siemens.com - 2012-02-04 14:46 -0500
                Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2012-02-03 22:35 +0000
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-06 00:01 -0500
                Re: Size of an arraylist in bytes Kaz Kylheku <kaz@kylheku.com> - 2012-02-06 08:46 +0000
                Re: Size of an arraylist in bytes Shao Miller <sha0.miller@gmail.com> - 2012-02-06 23:17 -0500
            Re: Size of an arraylist in bytes lawrence.jones@siemens.com - 2012-02-01 18:34 -0500
              Re: Size of an arraylist in bytes Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-08 10:54 -0800
    Re: Size of an arraylist in bytes Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 05:00 -0800

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