Re: On generally accepted terminology for pointers and arrays

From	"Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com>
Newsgroups	comp.lang.c++
Subject	Re: On generally accepted terminology for pointers and arrays
Date	2011-04-13 15:57 +0200
Organization	A noiseless patient Spider
Message-ID	<io4a43$l9k$1@dont-email.me> (permalink)
References	(1 earlier) <4da47fb0$0$25624$cc2e38e6@news.uslec.net> <io22nf$fm4$1@dont-email.me> <5t39q65tcht5bc7h7cuasnl4qeu0sqpqc5@4ax.com> <io2710$1hr$1@dont-email.me> <ia89q6tlh5hi93d2chk2nnks7s04lutga1@4ax.com>

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* cg_chas, on 12.04.2011 22:01:
> On Tue, 12 Apr 2011 20:52:13 +0200, "Alf P. Steinbach /Usenet"
> <alf.p.steinbach+usenet@gmail.com>  wrote:
>>
>> No, what Noah wrote, which is quoted in context above, was
>>
>>
>>    "To claim that a pointer points at anything other than what you get when you
>>     dereference it flies in the face ofthe concept of "pointer".
>
> Yes I read and understood his statement expressely for the face value of every
> word in the sentence.  Where we differ though is that I can see the greater
> value in his point regardless if he botched the wording or not.

I'm sure that with enough empathy any self-contradictory statement can be viewed 
as an attempted expression of some beautiful thought.

But, you can't require utmost precision of others, and think your own side is 
exempt from that requirement.

At least if you want to be taken seriously.

[snip]

> Since I can see the logic in your rebuttle to Noah, I am convinced that you are
> not ignorant to the importance of technical correctness and well-defined
> terminology.

Ah, good.

> So, let me ask you this directly. How does your logical assertion that an int*
> can "dynamically" point to an array fit into the pointer definition below?
>
> For a type T, T* is the type "pointer to T." That is, a variable of type T* can
> hold the address of an object of type T.

For most of us there is no problem.

Consider this function:

   void upcase( char* p )

If caller and implementor disagree on whether p points to single char object, or 
to a zero-terminated string, or whatever, then result might be core dump...

Now I pass by your desk and see you struggling with this function. Someone has 
noticed that too many core dumps seem to indicate that this 'upcase' function is 
the culprit, and you are attempting to fix it. As I pass you by you remark on 
the competentency (or lack thereof) of the original programmer, "jeez, this call 
to toupper passes negative values, he forgot to cast!".

I glance at it, and remark "he he, and he also seems to have assumed he's passed 
a pointer to a single char, instead of a pointer to a string!".

You say, "pointer to string? that's technically meaningless! see, here, it says 
'char*"

I think you're joking, and go on to whatever I was going to.

Two days later I notice that you're STILL struggling with the 'upcase' function.

What's going on, I ask you. How come you're still working on that trivial function?

As it turns out, after fixing the cast issue (which caused UB in the standard 
library) you thought you'd fixed it, but you got it back. No more core dumps, 
OK, but it doesn't pass the unit tests anymore. And you cannot figure out *why*.

I look at it, and say, "hey, that p, it's surely a pointer to a string?".

You just shake your head sadly, "Sorry Alf, that's meaningless, a 'char*' can't 
point to a string, it can only point to a 'char', that's what the type is about. 
But thanks for your attempt to help. Argh, this is really difficult: the code is 
trivial, yet it doesn't pass unit tests; do you have any other idea?"

I consider suggesting that you change the textual function declaration, like 
'void upcase( char s[] )', but it doesn't take more than a milli-second of 
reflection to see that you would not see the point of that. I could expect some 
retort like "Alf, Alf, thanks, but that means exactly the same, so it would not 
help with the unit test issue". And likewise for some other suggestions.

So, I just fetch myself yet another cup of coffee, and leave you to it.

Cheers & hth.,

- Alf

-- 
blog at <url: http://alfps.wordpress.com>

Thread

On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 04:00 +0200
  Re: On generally accepted terminology for pointers and arrays Pavel <pauldontspamtolk@removeyourself.dontspam.yahoo> - 2011-04-12 00:13 -0400
  Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 05:17 +0100
    Re: On generally accepted terminology for pointers and arrays Leigh Johnston <leigh@i42.co.uk> - 2011-04-12 14:02 +0100
      Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 14:10 +0100
        Re: On generally accepted terminology for pointers and arrays Leigh Johnston <leigh@i42.co.uk> - 2011-04-12 14:49 +0100
      Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-12 10:05 -0400
  Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-12 01:11 -0400
  Re: On generally accepted terminology for pointers and arrays gwowen <gwowen@gmail.com> - 2011-04-11 23:24 -0700
    Re: On generally accepted terminology for pointers and arrays gwowen <gwowen@gmail.com> - 2011-04-12 00:16 -0700
      Re: On generally accepted terminology for pointers and arrays Leigh Johnston <leigh@i42.co.uk> - 2011-04-12 13:53 +0100
        Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 14:08 +0100
      Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 14:05 +0100
        Re: On generally accepted terminology for pointers and arrays Leigh Johnston <leigh@i42.co.uk> - 2011-04-12 14:48 +0100
          Re: On generally accepted terminology for pointers and arrays Ian Collins <ian-news@hotmail.com> - 2011-04-13 07:53 +1200
      Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 22:14 +0200
        Re: On generally accepted terminology for pointers and arrays Öö Tiib <ootiib@hot.ee> - 2011-04-12 15:39 -0700
    Re: On generally accepted terminology for pointers and arrays Goran <goran.pusic@gmail.com> - 2011-04-12 01:39 -0700
      Re: On generally accepted terminology for pointers and arrays Ian Collins <ian-news@hotmail.com> - 2011-04-12 20:51 +1200
    Re: On generally accepted terminology for pointers and arrays Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-04-12 21:51 +0000
  Re: On generally accepted terminology for pointers and arrays cpp4ever <n2xssvv.g02gfr12930@ntlworld.com> - 2011-04-12 09:59 +0100
    Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 16:25 +0200
      Re: On generally accepted terminology for pointers and arrays cpp4ever <n2xssvv.g02gfr12930@ntlworld.com> - 2011-04-12 16:07 +0100
        Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 17:32 +0200
          Re: On generally accepted terminology for pointers and arrays cpp4ever <n2xssvv.g02gfr12930@ntlworld.com> - 2011-04-12 16:53 +0100
            Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 18:16 +0200
              Re: On generally accepted terminology for pointers and arrays cpp4ever <n2xssvv.g02gfr12930@ntlworld.com> - 2011-04-12 17:39 +0100
                Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 19:32 +0200
                Re: DILLIGAF cpp4ever <n2xssvv.g02gfr12930@ntlworld.com> - 2011-04-12 19:05 +0100
                Re: DILLIGAF Peter Remmers <p.remmers@expires-2011-04-30.arcornews.de> - 2011-04-12 20:36 +0200
                Re: DILLIGAF cpp4ever <n2xssvv.g02gfr12930@ntlworld.com> - 2011-04-12 20:47 +0100
                Re: DILLIGAF gwowen <gwowen@gmail.com> - 2011-04-12 14:48 -0700
                Re: DILLIGAF Öö Tiib <ootiib@hot.ee> - 2011-04-12 15:16 -0700
    Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 17:48 +0100
  Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-12 09:37 -0700
    Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 18:34 +0100
    Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 19:38 +0200
      Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-12 11:00 -0700
        Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 20:03 +0200
          Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-12 11:06 -0700
            Re: On generally accepted terminology for pointers and arrays Peter Remmers <p.remmers@expires-2011-04-30.arcornews.de> - 2011-04-12 20:26 +0200
              Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-12 11:33 -0700
                Re: On generally accepted terminology for pointers and arrays Peter Remmers <p.remmers@expires-2011-04-30.arcornews.de> - 2011-04-12 20:55 +0200
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 20:14 +0100
                Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-12 12:47 -0700
                Re: On generally accepted terminology for pointers and arrays Peter Remmers <p.remmers@expires-2011-04-30.arcornews.de> - 2011-04-12 22:40 +0200
      Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-12 14:15 -0400
        Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-12 20:52 +0200
          Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 20:23 +0100
          Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-12 16:01 -0400
            Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-12 13:46 -0700
              Re: On generally accepted terminology for pointers and arrays Öö Tiib <ootiib@hot.ee> - 2011-04-12 19:49 -0700
                Re: On generally accepted terminology for pointers and arrays hanukas <jukka@liimatta.org> - 2011-04-13 00:06 -0700
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 04:14 -0400
                Re: On generally accepted terminology for pointers and arrays Öö Tiib <ootiib@hot.ee> - 2011-04-13 07:53 -0700
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 09:52 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 05:20 -0400
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 10:31 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 07:04 -0400
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 12:35 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 07:41 -0400
                Re: On generally accepted terminology for pointers and arrays Ian Collins <ian-news@hotmail.com> - 2011-04-14 07:47 +1200
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-14 11:44 +0100
                Re: On generally accepted terminology for pointers and arrays "io_x" <a@b.c.invalid> - 2011-04-13 18:41 +0200
                Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-13 09:35 -0700
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 20:17 +0100
              Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 04:33 -0400
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 04:35 -0400
            Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 01:19 +0100
              Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 04:01 -0400
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 04:20 -0400
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 09:56 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 05:24 -0400
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 10:34 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 07:07 -0400
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 12:36 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 07:43 -0400
                Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-13 13:18 +0100
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 08:30 -0400
            Re: On generally accepted terminology for pointers and arrays "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-04-13 15:57 +0200
              Re: On generally accepted terminology for pointers and arrays Leigh Johnston <leigh@i42.co.uk> - 2011-04-13 15:10 +0100
              Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 11:09 -0400
                Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 12:04 -0400
            Re: On generally accepted terminology for pointers and arrays Noah Roberts <dont@email.me> - 2011-04-13 09:56 -0700
              Re: On generally accepted terminology for pointers and arrays cg_chas <cg_chas@hotmail.com> - 2011-04-13 14:11 -0400
      Re: On generally accepted terminology for pointers and arrays "Paul" <pchristor@yahoo.co.uk> - 2011-04-12 19:29 +0100
  Re: On generally accepted terminology for pointers and arrays Joshua Maurice <joshuamaurice@gmail.com> - 2011-04-12 09:36 -0700

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