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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: A portable stack in C |
| Date | 2011-11-15 15:07 -0800 |
| Organization | None to speak of |
| Message-ID | <ln7h310ytm.fsf@nuthaus.mib.org> (permalink) |
| References | (8 earlier) <j9tpaq$lq0$1@speranza.aioe.org> <0.14403af903e96e9e0bb8.20111115153135GMT.8739dptnag.fsf@bsb.me.uk> <ln1ut92jle.fsf@nuthaus.mib.org> <0.5da9481d0e3557b1de10.20111115211559GMT.87r519rss0.fsf@bsb.me.uk> <slrnjc5q62.1tp6.willem@toad.stack.nl> |
Willem <willem@toad.stack.nl> writes:
> Ben Bacarisse wrote:
> ) Keith Thompson <kst-u@mib.org> writes:
> )
> )> Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
> )>> jacob navia <jacob@spamsink.net> writes:
> )> [...]
> )>>> You will agree that *p is the same as p[0] isn't it? For ALL p?
> )>>
> )>> Kinda. It's true in the sense that you get the same result when the
> )>> result is defined, and that both are undefined if either one is
> )>> undefined. Are two "undefined behaviours" always "the same"? A thread
> )>> about that could run and run.
> )>
> )> And it's not true of p is a function pointer.
> )
> ) Surely both *p and p[0] are undefined in that case.
>
> Well, technically what you just said is meaningless, you see,
> 'undefined' is not a value that a variable can take in C.
>
> Pedantically, it is 'undefined behaviour' to access both these values.
> The behaviour need not be the same for those two cases. But then again, it
> need not be the same when you compare the first case with the first case.
No, the first is well-defined and the second is a constraint violation.
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-14 17:54 +0100
Re: A portable stack in C Barry Schwarz <schwarzb@dqel.com> - 2011-11-14 20:55 -0800
Re: A portable stack in C jacob navia <jacob@spamsink.net> - 2011-11-15 09:22 +0100
Re: A portable stack in C Ike Naar <ike@iceland.freeshell.org> - 2011-11-15 09:00 +0000
Re: A portable stack in C jacob navia <jacob@spamsink.net> - 2011-11-15 11:26 +0100
Re: A portable stack in C "BartC" <bc@freeuk.com> - 2011-11-15 10:05 +0000
Re: A portable stack in C jacob navia <jacob@spamsink.net> - 2011-11-15 11:25 +0100
Re: A portable stack in C "BartC" <bc@freeuk.com> - 2011-11-15 11:08 +0000
Re: A portable stack in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 11:45 +0000
Re: A portable stack in C jacob navia <jacob@spamsink.net> - 2011-11-15 12:57 +0100
Re: A portable stack in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 12:39 +0000
Re: A portable stack in C jacob navia <jacob@spamsink.net> - 2011-11-15 14:26 +0100
Re: A portable stack in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 15:31 +0000
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-15 12:53 -0800
Re: A portable stack in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 21:15 +0000
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-15 14:29 -0800
Re: A portable stack in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 22:59 +0000
Re: A portable stack in C James Kuyper <jameskuyper@verizon.net> - 2011-11-15 17:30 -0500
Re: A portable stack in C Willem <willem@toad.stack.nl> - 2011-11-15 22:33 +0000
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-15 15:07 -0800
Re: A portable stack in C Seebs <usenet-nospam@seebs.net> - 2011-11-15 22:37 +0000
Re: A portable stack in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-15 23:01 +0000
Re: A portable stack in C "BartC" <bc@freeuk.com> - 2011-11-15 18:45 +0000
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-15 12:41 -0800
Re: A portable stack in C Richard Damon <news.x.richarddamon@xoxy.net> - 2011-11-15 23:07 -0500
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-15 20:18 -0800
Re: A portable stack in C Robert Wessel <robertwessel2@yahoo.com> - 2011-11-15 22:53 -0600
Re: A portable stack in C "BartC" <bc@freeuk.com> - 2011-11-16 12:00 +0000
Re: A portable stack in C falk@rahul.net (Edward A. Falk) - 2011-11-16 16:08 +0000
Re: A portable stack in C David Thompson <dave.thompson2@verizon.net> - 2012-01-19 02:41 -0500
Re: A portable stack in C Thomas David Rivers <rivers@dignus.com> - 2011-11-15 11:21 -0500
Re: A portable stack in C Barry Schwarz <schwarzb@dqel.com> - 2011-11-15 17:53 -0800
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-15 19:21 +0100
Re: A portable stack in C Barry Schwarz <schwarzb@dqel.com> - 2011-11-15 17:53 -0800
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-18 08:13 +0100
Re: A portable stack in C Rui Maciel <rui.maciel@gmail.com> - 2011-11-15 10:14 +0000
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-15 19:20 +0100
Re: A portable stack in C Acid Washed China Blue Jeans <chine.bleu@yahoo.com> - 2011-11-15 08:13 -0800
Re: A portable stack in C Kaz Kylheku <kaz@kylheku.com> - 2011-11-15 16:27 +0000
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-15 19:21 +0100
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-15 13:19 -0800
Re: A portable stack in C blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-11-17 15:45 +0000
Re: A portable stack in C John Gordon <gordon@panix.com> - 2011-11-17 15:56 +0000
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-17 18:02 +0100
Re: A portable stack in C "BartC" <bc@freeuk.com> - 2011-11-17 17:35 +0000
Re: A portable stack in C Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-11-17 18:45 +0100
Re: A portable stack in C Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-18 00:27 -0800
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-18 10:40 +0100
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-20 07:22 +0100
Re: A portable stack in C Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-21 00:38 -0800
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-21 03:44 -0600
Re: A portable stack in C Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-21 13:00 +0200
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-21 06:07 -0600
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-21 03:50 -0600
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-21 07:48 -0600
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-21 20:11 +0100
Re: A portable stack in C "BartC" <bc@freeuk.com> - 2011-11-18 12:47 +0000
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-18 23:31 -0600
Re: A portable stack in C blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-11-18 14:45 +0000
Re: A portable stack in C James Kuyper <jameskuyper@verizon.net> - 2011-11-18 10:14 -0500
Re: A portable stack in C Keith Thompson <kst-u@mib.org> - 2011-11-18 12:20 -0800
Re: A portable stack in C blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-11-19 17:23 +0000
Re: A portable stack in C Seebs <usenet-nospam@seebs.net> - 2011-11-19 18:49 +0000
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-19 22:41 -0600
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-20 07:27 +0100
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-21 20:12 +0100
Re: A portable stack in C "io_x" <a@b.c.invalid> - 2011-11-20 07:50 +0100
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-21 01:24 -0600
Re: A portable stack in C Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-21 05:22 -0800
Re: A portable stack in C "Jo" <none@none.none> - 2011-11-22 03:31 -0600
Re: A portable stack in C 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-21 06:38 -0800
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