Re: C pointer semantics with dynamically allocated struct

From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: C pointer semantics with dynamically allocated struct
Date	2015-10-07 16:21 -0700
Organization	None to speak of
Message-ID	<ln1td6jmdc.fsf@kst-u.example.com> (permalink)
References	(16 earlier) <5861f87d-0660-44af-ba33-3b5f00a76508@googlegroups.com> <lnegh6k10i.fsf@kst-u.example.com> <81267d1a-e9c6-4831-87f2-f6cf5248a7c5@googlegroups.com> <ln612ijtdz.fsf@kst-u.example.com> <d4a54a0b-a2a9-4165-9c53-9d32e9198e58@googlegroups.com>

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supercat@casperkitty.com writes:
> On Wednesday, October 7, 2015 at 3:50:14 PM UTC-5, Keith Thompson wrote:
>> If the Standard says code *shall* not do X, and the word "shall" is not
>> in a constraint, then (again, ignoring 4p1) it does not "prohibit" doing
>> X.  That's because the Standard is using the word "shall" in a specific
>> technical sense that doesn't necessarily match common English usage.
>
> I'd say it's actually misusing the word "shall" in a sense which doesn't
> really match any other usage anywhere that I can think of, since generally
> when a standard mandates that an X shall do Y, that implies that from the
> point of view of the standard, the fact that something fails to do Y is
> sufficient in and of itself to imply that--from the point of view of the
> standard--the thing in question is, *by definition*, not a legitimate X.
>
> Can you think of any other standards which use the word "shall" in the
> same way as the C Standard applies it to run-time behavior?

No, though other standards do use the word "shall" in somewhat
idiosyncratic ways.  But the C standard does use it that way, and has
consistently done so for 26 years.  Once you know how the standard uses
the word "shall", the meaning is in my opinion crystal clear.

The standard does not say that pointer-based type-punning is prohibited.
It says that its behavior is undefined.  Do you not get that?

>> If you want to argue that you're using the word "prohibition" in the
>> sense that the standard uses it in 4p1, then you have a point -- but I
>> don't *think* that's what you're doing (please correct me if I'm
>> mistaken on that point).
>
> Suppose an implementation specifies that a pointer of any type identifies
> a machine address, that a write to a uint32_t* identifying the first byte
> of a word will cause the indicated value to be stored in that byte and
> the next three in LSB-first format, and that a read of a uint16_t* which
> identifies the first or third byte of a word will cause the values held
> in that byte and the next one to be interpreted as a 16-bit unsigned
> integer in LSB-first format.
>
> Suppose further that the implementation makes no reference whatsoever to
> N1570 6.5p7.

I presume you mean that it doesn't *explicitly* refer to 6.5p7.  (Any
implementation that claims to conform to the standard implicitly refers
to all of it.)

> Would someone writing code for such an implementation be entitled to expect
> that casting the address of a "uint32_t" to "uint16_t*" and reading it
> would yield the low-order 16 bits of the 32-bit value?  A lot of people
> seem to think that the answer would be "no", because of N1570 6.5p7.

"A lot of people"?  Name one.

Certainly if an implementation documents the behavior of such code,
you're entitled to expect the implementation to behave as its
documentation says it does.  The standard doesn't define the behavior;
that in no way implies that an implementation can't define the behavior.

Of course if the implementation fails to obey its own documentation,
that's not a violation of the C standard -- but presumably you'd still
be entitled to submit a bug report and/or get your money (if any) back.

> Perhaps rather than getting caught up on the word "prohibition", perhaps
> it would be better to focus on a point that should be non-controversial:
>
>   It should not be possible for a non-defective standard to be reasonably
>   interpreted as saying that a a programmer is entitled to expect that a
>   certain construct will yield a certain behavior on a particular platform
>   whose documentation conforms with the requirements imposed by the Standard,
>   but also be possible for it to be reasonably interpreted as saying that
>   a compiler for that same platform with that same documentation would be
>   entitled to expect that a program will never receive input that would
>   cause such a construct to be executed.
>
>   A good standard should minimize the number of cases where there might be
>   disagreements, but I would posit that for a standard to be considered as
>   non-defective, it must ensure that in every place that was ambiguous,
>   either programmers were clearly not entitled to expectations (and the only
>   ambiguity would be whether compilers were entitled to take advantage of
>   this) or else compilers were clearly not entitled to expectations (and
>   the only ambiguity was whether programmers were entitled to take advantage
>   of that)
>
> To my mind, the fact that the parts of the C standard admit to common
> contradictory readings would imply that those parts are defective.  Alas,
> I have a sneaking suspicion that there are two competing factions who both
> believe that N1570 6.5p7 supports their view and will never agree to any
> alternate wording which would contradict that view.

N1570 6.5p7 says that if a program accesses an object's stored value by
an lvalue that doesn't have one of the listed types, then that program's
behavior *is not defined by the standard*.  That's all it says.

The only way I can think of that someone could reach a different
conclusion is if they didn't know how the standard uses the word
"shall".

> IMHO, the proper solution is
[snip]

I don't see how we can discuss a solution without defining what the
problem is, and I don't believe we can do that without understanding
what the standard actually says.  Your insistence on using the word
"prohibition" (assuming you're not basing your using on 4p1) indicates
to me either than you don't understand what the Standard actually says,
or that I don't understand what you're saying.

As I've said before, I think you have some interesting ideas.  But if we
can't agree on what the standard actually says, it's going to be
impossible to discuss them meaningfully.

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Thread

Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-09-29 09:49 -0700
  Re: C pointer semantics with dynamically allocated struct wssimms@gmail.com - 2015-09-30 21:18 -0700
    Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-01 09:35 -0700
      Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-01 09:41 -0700
        Re: C pointer semantics with dynamically allocated struct gazelle@shell.xmission.com (Kenny McCormack) - 2015-10-01 18:34 +0000
          Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-01 12:02 -0700
    Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-02 13:03 +0000
      Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-02 06:20 -0700
        Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 16:07 +0100
          Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-02 08:46 -0700
            Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 17:28 +0100
              Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-02 10:30 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 20:32 +0100
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-02 12:58 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 22:06 +0100
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-03 09:31 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-03 14:31 -0700
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-03 09:27 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-03 20:36 +0100
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-03 13:00 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-03 23:37 +0100
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-03 17:07 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-03 17:42 -0700
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-03 17:49 -0700
                Re: C pointer semantics with dynamically allocated struct Richard Damon <Richard@Damon-Family.org> - 2015-10-03 23:28 -0400
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-04 00:10 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-04 13:24 +0100
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-04 14:07 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-04 14:40 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-04 18:04 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-04 20:10 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-04 22:15 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-05 08:53 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-06 08:45 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-06 12:34 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-06 17:16 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-06 21:47 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-07 11:05 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-07 11:47 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-07 13:50 -0700
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-07 18:10 -0400
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-07 16:10 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-07 16:33 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-08 09:08 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-08 10:43 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-08 11:50 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-08 12:19 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-07 15:32 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-07 16:21 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-08 08:54 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-08 11:15 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-08 12:38 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-08 13:30 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-08 14:15 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-08 14:53 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-08 15:23 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-08 17:24 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-09 08:02 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-09 09:02 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-09 12:43 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-09 14:21 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-09 15:14 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-13 18:37 -0700
                Re: C pointer semantics with dynamically allocated struct Martin Shobe <martin.shobe@yahoo.com> - 2015-10-07 20:56 -0500
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-07 19:41 -0700
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-07 23:15 -0400
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-14 10:05 +0000
                Re: C pointer semantics with dynamically allocated struct Richard Heathfield <rjh@cpax.org.uk> - 2015-10-14 11:23 +0100
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-14 08:24 -0700
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-16 11:12 +0000
                Re: C pointer semantics with dynamically allocated struct Gareth Owen <gwowen@gmail.com> - 2015-10-16 21:55 +0100
                Re: C pointer semantics with dynamically allocated struct Les Cargill <lcargill99@comcast.com> - 2015-10-16 22:08 -0500
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-14 11:44 -0400
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-14 11:12 -0700
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-07 10:34 +0000
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-07 07:23 -0400
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-07 09:53 -0700
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-14 10:13 +0000
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-14 11:36 -0400
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-04 13:35 +0100
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-04 06:23 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-04 15:34 +0100
                Re: C pointer semantics with dynamically allocated struct "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-04 08:07 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-04 14:42 +0000
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-04 15:37 +0000
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-05 00:33 +0100
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-14 10:20 +0000
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-14 13:55 +0100
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-04 22:06 -0700
                Re: C pointer semantics with dynamically allocated struct raltbos@xs4all.nl (Richard Bos) - 2015-10-14 10:30 +0000
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-14 08:39 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-14 23:47 +0000
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-15 10:20 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-15 11:10 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-15 12:11 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-15 12:35 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-15 13:52 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-15 14:35 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-15 15:51 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-16 06:48 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-16 08:50 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-16 10:06 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-16 12:45 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-16 13:56 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-16 14:29 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-16 14:52 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-16 15:32 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-16 15:59 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-17 00:03 +0000
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-17 00:08 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 15:26 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-17 16:38 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-16 23:43 +0000
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-16 23:57 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 14:50 -0700
                Re: C pointer semantics with dynamically allocated struct Ian Collins <ian-news@hotmail.com> - 2015-10-18 10:55 +1300
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-17 18:24 -0400
                Re: C pointer semantics with dynamically allocated struct Richard Damon <Richard@Damon-Family.org> - 2015-10-17 18:39 -0400
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-17 18:56 -0400
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 16:17 -0700
                Re: C pointer semantics with dynamically allocated struct James Kuyper <jameskuyper@verizon.net> - 2015-10-18 11:46 -0400
                Re: C pointer semantics with dynamically allocated struct Richard Damon <Richard@Damon-Family.org> - 2015-10-17 19:44 -0400
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-17 16:48 -0700
                Re: C pointer semantics with dynamically allocated struct Richard Heathfield <rjh@cpax.org.uk> - 2015-10-18 01:14 +0100
                Re: C pointer semantics with dynamically allocated struct Richard Damon <Richard@Damon-Family.org> - 2015-10-17 20:22 -0400
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-17 17:26 -0700
                Re: C pointer semantics with dynamically allocated struct Richard Heathfield <rjh@cpax.org.uk> - 2015-10-18 01:44 +0100
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 20:09 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-18 11:24 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-19 04:42 +0000
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-19 16:24 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-20 02:20 +0000
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-19 19:53 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-20 09:41 +0000
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 19:53 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 16:07 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-17 14:55 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-18 04:28 +0000
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-15 12:49 -0700
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-15 12:26 -0700
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-15 12:48 -0700
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-17 08:21 -0700
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-04 22:23 -0700
          Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-02 09:10 -0700
            Re: C pointer semantics with dynamically allocated struct Martin Shobe <martin.shobe@yahoo.com> - 2015-10-02 11:58 -0500
              Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-02 11:38 -0700
                Re: C pointer semantics with dynamically allocated struct Martin Shobe <martin.shobe@yahoo.com> - 2015-10-05 09:36 -0500
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-12 09:47 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-13 02:51 +0000
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-12 23:45 -0700
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-15 13:54 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-16 01:07 +0000
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-19 15:33 -0700
            Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 19:21 +0100
              Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-02 12:10 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 21:24 +0100
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-02 14:32 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 23:43 +0100
                Re: C pointer semantics with dynamically allocated struct supercat@casperkitty.com - 2015-10-02 16:49 -0700
                Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-03 02:01 +0100
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-03 00:38 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-02 16:10 -0700
                Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-04 21:54 -0700
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-05 08:19 -0700
          Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-02 15:16 -0700
            Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-02 22:52 +0000
              Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-03 00:48 -0700
                Re: C pointer semantics with dynamically allocated struct glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-03 08:22 +0000
                Re: C pointer semantics with dynamically allocated struct Keith Thompson <kst-u@mib.org> - 2015-10-03 12:05 -0700
              Re: C pointer semantics with dynamically allocated struct Richard Damon <Richard@Damon-Family.org> - 2015-10-03 16:38 -0400
            Re: C pointer semantics with dynamically allocated struct Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-03 00:00 +0100
              Re: C pointer semantics with dynamically allocated struct Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-04 22:16 -0700

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