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Groups > comp.std.c > #1448

Re: Initial draft proposal: "Safe arrays and pointers for C"

From Hans-Bernhard Bröker <HBBroeker@t-online.de>
Newsgroups comp.std.c
Subject Re: Initial draft proposal: "Safe arrays and pointers for C"
Date 2012-08-15 00:37 +0200
Message-ID <a9028hF8rcU1@mid.dfncis.de> (permalink)
References (2 earlier) <k0cfg2$7a5$1@dont-email.me> <lnr4rarqqz.fsf@nuthaus.mib.org> <k0e4tl$892$1@dont-email.me> <a8vm2oFd68U1@mid.dfncis.de> <k0ec5g$ns5$1@dont-email.me>

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On 14.08.2012 22:24, John Nagle wrote:
> On 8/14/2012 12:09 PM, Hans-Bernhard Bröker wrote:
>> On 14.08.2012 20:20, John Nagle wrote:
>>> On 8/13/2012 10:23 PM, Keith Thompson wrote:
>>
>>>> C does not have parameters of array type.  "a" is not an array, it's a
>>>> pointer.
>
>      It's a fully qualified array pointer,

It is not, and it cannot be, because such a thing as an "array pointer" 
does not exist in C.  There are pointers to arrays (the abovementioned 
'a' is one), and there arrays of pointers, but no "array pointers".

Nor did "fully qualified" have any meaning in this language, last I 
looked.  That's C++ speak.

I will ignore and snip all references to this imaginary entity from here on.

> which has most of the behaviors of an array.

Not more so than any other pointer would.  Which makes sense, since it 
_is_ a pointer.

>      True.  And here's the mess it creates, even for a fixed size array:
>
> typedef double mat4[4][4];
> void fn1(mat4 m0)
> {   mat4 m1;
>      size_t s0 = sizeof(m0);
>      size_t s1 = sizeof(m1);
>      printf("Size of m0 is %d.\nSize of m1 is %d", s0, s1);
> }
>
> Size of m0 is 4.
> Size of m1 is 128
>
> This is not good.

That's only a mess if you want it to be one.

>>> It's certainly desirable to be able to obtain the size of an array
>>> when the language knows it.
>>
>> But in the case at hand the language _doesn't_ know it.
>
>     Array size information is used for subscript calculations for
> multidimensional array parameters.

That only considers the size for the inner dimensions.  The one we're 
looking at here is the outermost dimension --- and that's neither used 
nor needed for that.

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Thread

Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-13 11:39 -0700
  Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-13 23:23 +0200
    Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-13 17:04 -0700
    Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-13 20:08 -0700
      Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-13 22:23 -0700
        Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 11:20 -0700
          Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 14:54 -0400
            Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 21:09 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 16:00 -0400
            Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 18:08 -0400
              Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-14 23:05 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 06:48 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 11:22 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 15:13 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 13:00 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 22:52 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 17:18 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-16 19:20 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 13:40 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-16 11:04 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 14:35 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-16 11:47 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 14:52 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 14:41 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2012-08-16 12:39 +0100
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-16 09:57 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 13:28 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2012-08-16 23:52 +0100
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 18:56 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 19:23 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-15 21:47 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-16 19:14 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-16 20:28 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 15:05 -0400
          Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-14 21:09 +0200
            Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 13:24 -0700
              Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 16:39 -0400
              Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 15:23 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-14 22:58 -0700
              Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 00:37 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 16:42 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 22:57 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 17:02 -0700
          Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 14:59 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 15:35 -0700
              Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 00:51 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 06:43 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 08:31 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 09:14 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 18:58 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 06:45 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-14 22:51 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 07:18 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 14:15 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 14:28 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 14:36 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 14:54 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 15:08 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 12:50 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 23:22 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 14:38 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-16 00:51 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 16:32 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-16 09:05 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 17:22 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 20:29 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 12:36 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 16:09 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 08:47 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 16:33 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 16:38 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 06:46 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 22:28 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 08:34 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 09:12 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-16 13:09 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Wojtek Lerch <wojtek_l@yahoo.ca> - 2012-08-16 16:21 -0400
              Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-16 14:22 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-16 15:28 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Wojtek Lerch <wojtek_l@yahoo.ca> - 2012-08-16 19:49 -0400
      Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 08:56 +0200
      Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 06:18 -0400
        Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 12:42 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 09:43 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-14 19:52 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-14 21:03 +0200
            Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 21:39 +0200
      Re: Initial draft proposal: "Safe arrays and pointers for C" Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-08-14 08:26 -0400
  Re: Initial draft proposal: "Safe arrays and pointers for C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-13 22:44 +0100
    Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-13 18:05 -0700
  Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-14 21:00 +0200
    Re: Initial draft proposal: "Safe arrays and pointers for C" Marc <marc.glisse@gmail.com> - 2012-08-14 21:18 +0000
      Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-14 23:51 +0200
  Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-17 09:40 -0700
    Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-17 21:00 +0200
      Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-17 13:30 -0700
        Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-17 23:14 +0200
        Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-18 01:07 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-19 23:14 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Ike Naar <ike@sverige.freeshell.org> - 2012-08-20 07:16 +0000
              Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-20 00:25 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-20 11:49 +0200
            Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-20 22:40 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-20 23:08 +0200
    Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-17 15:33 -0700

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