Re: Compatibility question

From	"BartC" <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Re: Compatibility question
Date	2012-10-24 00:57 +0100
Organization	A noiseless patient Spider
Message-ID	<k67avm$o03$1@dont-email.me> (permalink)
References	<OYMHVs.wix.4bcJD@gmail.com><0.a87a1c8a472d870b0466.20121022022701BST.87y5izxpne.fsf@bsb.me.uk><JLOhFS.Dvd.FY9Iy@gmail.com><0.d779297035d2edccd1b4.20121022173052BST.87ehkqbhab.fsf@bsb.me.uk><2nYjPo.Krd.2aRbe@gmail.com> <lnfw56fl74.fsf@nuthaus.mib.org><qRFu8I.lcH.7XEwQ@gmail.com><0.5ef6d4d4944842791bc8.20121022210639BST.87pq4a9sq8.fsf@bsb.me.uk><ap54B1.hSk.bor8X@gmail.com> <lnr4opdm7m.fsf@nuthaus.mib.org><VTQKnL.Au1.NMBnf@gmail.com> <lnzk3cvlzy.fsf@nuthaus.mib.org>

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"Keith Thompson" <kst-u@mib.org> wrote in message 
news:lnzk3cvlzy.fsf@nuthaus.mib.org...
> Steve Thompson <stevet810@gmail.com> writes:

>> No, a char ** object is a pointer to a char ** object.
>
> Was that really what you meant to type?  I messed up the number of *s,
> so I can hardly criticize you for doing the same thing, but I'd like to
> know what you meant.
>
> In your model, as I understand it, an int object is really a pointer to
> int, or an int*.  It would follow that a char** object is really a
> pointer to a char**, or a char***.  Or am I misunderstanding you?
>
> In fact, an int object is an int object.  I find that so obvious
> that it seems odd to have to state it.  For an operation on such
> an object, a compiler might have to generate code that determines
> that object's address.

For every variable of type T, there will be an address of the variable of 
type T* (at least, before compiler optimisation gets to work on it). That 
address (or pointer) will be a constant value though, just like the constant 
8258 is value of type int that doesn't need storage. Such an address is also 
automatically dereferenced by a HLL when you just write the name of the 
variable; so the T* aspects of it get overlooked.

That's how you might get your char*** pointer from char**. Of course ST 
might have been thinking of an implementation with an actual stored char*** 
pointer, not a constant one, in which case the address of that, if his 
language allows it, would be char****!

>>> I think you're simply adding an extra -- and unnecessary -- level
>>> of indirection, and of confusion.

Whoever said that bit is right. I think a diagram is called for.

-- 
Bartc

Thread

Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-20 03:08 +0000
  Re: Compatibility question Ian Collins <ian-news@hotmail.com> - 2012-10-20 16:20 +1300
    Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-20 11:50 +0100
      Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-20 11:41 -0700
        Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-21 23:04 +0000
          Re: Compatibility question Barry Schwarz <schwarzb@dqel.com> - 2012-10-21 20:27 -0700
    Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-20 04:01 +0000
      Re: Compatibility question Ian Collins <ian-news@hotmail.com> - 2012-10-21 09:26 +1300
        Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-21 22:54 +0000
          Re: Compatibility question Ian Collins <ian-news@hotmail.com> - 2012-10-22 12:29 +1300
            Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-21 23:50 +0000
              Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-22 02:27 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 02:28 +0000
                Re: Compatibility question Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-22 11:18 -0400
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 16:19 +0000
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-22 17:37 +0100
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-22 17:40 +0100
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-22 17:30 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 17:23 +0000
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-22 10:52 -0700
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 18:42 +0000
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-22 21:06 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 22:52 +0000
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-23 03:33 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-23 12:28 +0000
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-23 16:45 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-23 17:53 +0000
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-23 12:41 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-23 21:28 +0100
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-23 20:57 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-23 12:26 -0700
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-23 20:39 +0000
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-23 15:53 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-24 00:57 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-23 20:06 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-24 11:18 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-24 12:04 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-24 23:10 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-24 16:58 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-25 01:46 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-24 19:40 -0700
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-24 20:20 +0000
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-24 14:38 -0700
                Re: Compatibility question James Kuyper <jameskuyper@verizon.net> - 2012-10-24 17:55 -0400
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-24 16:29 -0700
                Re: Compatibility question Greg Martin <greg@softsprocket.com> - 2012-10-24 15:21 -0700
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-26 03:30 +0000
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-26 13:02 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-27 00:04 +0000
                Re: Compatibility question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-27 20:15 +0100
                Re: Compatibility question Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2012-10-27 16:36 -0600
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-28 17:36 +0000
                Re: Compatibility question Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-10-27 22:42 +0300
                Re: Compatibility question Greg Martin <greg@softsprocket.com> - 2012-10-27 14:30 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-27 22:57 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-27 17:04 -0700
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-27 17:14 -0700
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-27 18:04 -0700
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-24 16:46 -0700
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-25 01:18 +0000
                Re: Compatibility question Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-10-27 21:08 +0300
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-28 17:38 +0000
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-23 00:38 +0100
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-22 16:50 -0700
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-23 12:33 +0000
                Re: Compatibility question Öö Tiib <ootiib@hot.ee> - 2012-10-22 14:23 -0700
                Re: Compatibility question James Kuyper <jameskuyper@verizon.net> - 2012-10-22 17:26 -0400
                Re: Compatibility question Ian Collins <ian-news@hotmail.com> - 2012-10-23 10:55 +1300
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 23:27 +0000
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-22 22:44 +0100
                Re: Compatibility question Les Cargill <lcargill99@comcast.com> - 2012-10-22 17:15 -0500
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-23 00:13 +0100
                Re: Compatibility question James Kuyper <jameskuyper@verizon.net> - 2012-10-22 18:35 -0400
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-23 00:14 +0100
                Re: Compatibility question Steve Thompson <stevet810@gmail.com> - 2012-10-22 23:42 +0000
                Re: Compatibility question Ian Collins <ian-news@hotmail.com> - 2012-10-23 13:35 +1300
                Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-22 17:01 -0700
                Re: Compatibility question "BartC" <bc@freeuk.com> - 2012-10-23 01:47 +0100
              Re: Compatibility question Keith Thompson <kst-u@mib.org> - 2012-10-21 19:27 -0700

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