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| From | pacman@kosh.dhis.org (Alan Curry) |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: References in C |
| Date | 2011-06-27 22:21 +0000 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <iuavpt$5hl$1@speranza.aioe.org> (permalink) |
| References | <iu1iku$4k9$1@speranza.aioe.org> <iu8g01$7nu$1@dont-email.me> <iu9aos$vjt$1@speranza.aioe.org> <iua9cs$isu$1@dont-email.me> |
In article <iua9cs$isu$1@dont-email.me>,
Shao Miller <sha0.miller@gmail.com> wrote:
>
>On 6/27/2011 03:16, Alan Curry wrote:
>> The use of the C++ reference didn't make testing for NULL unnecessary; it
>> merely made testing for NULL impossible.
>>
>
>What about with:
>
> #include <assert.h>
>
> int main(void) {
> int * ip = 0;
> int & i = *ip;
> assert(&i);
> return 0;
> }
>
>Does the assertion check for a, let's say, "null reference"?
You're right. It's not impossible to check for a null reference. You just
have to think outside the box.
#include <stdio.h>
void foo(int &iref)
{
if(&iref == NULL) {
printf("&iref is null. How about that!\n");
return;
}
iref = 42;
}
int main(void)
{
int *whoops = 0;
foo(*whoops);
return 0;
}
I'm sure this is all formally undefined. But it shows that references are
purely an alternate syntax for pointers and don't provide any real
"protection" against unexpected NULLs. You're just depending on your caller
to have already done the check.
All functions depend on their callers being sane; new syntax won't change
that.
--
Alan Curry
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References in C jacob navia <jacob@spamsink.net> - 2011-06-24 10:42 +0200
Re: References in C BGB <cr88192@hotmail.com> - 2011-06-24 02:53 -0700
Re: References in C Ian Collins <ian-news@hotmail.com> - 2011-06-24 22:10 +1200
Re: References in C "BartC" <bc@freeuk.com> - 2011-06-24 11:14 +0100
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-24 16:59 +0200
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-24 09:26 -0400
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-24 20:08 +0200
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-24 11:40 -0700
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-24 14:53 -0400
Re: References in C jt@toerring.de (Jens Thoms Toerring) - 2011-06-24 20:44 +0000
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-24 23:09 +0200
Re: References in C Joe Wright <joewwright@comcast.net> - 2011-06-24 17:38 -0400
Re: References in C "BartC" <bc@freeuk.com> - 2011-06-24 22:58 +0100
Re: References in C Ian Collins <ian-news@hotmail.com> - 2011-06-25 10:11 +1200
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-26 17:00 -0500
Re: References in C "BartC" <bc@freeuk.com> - 2011-06-26 22:55 +0100
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-26 18:25 -0500
Re: References in C "BartC" <bc@freeuk.com> - 2011-06-26 23:38 +0100
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-26 19:19 -0500
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-27 01:27 +0200
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-26 19:13 -0700
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Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-27 06:55 +0200
Re: References in C Ian Collins <ian-news@hotmail.com> - 2011-06-27 17:10 +1200
Re: References in C lawrence.jones@siemens.com - 2011-06-27 10:04 -0400
Re: References in C jt@toerring.de (Jens Thoms Toerring) - 2011-06-26 22:54 +0000
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-27 01:29 +0200
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-26 19:39 -0500
Re: References in C pacman@kosh.dhis.org (Alan Curry) - 2011-06-27 07:16 +0000
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-27 09:46 +0200
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-27 12:03 -0400
Re: References in C Stephen Sprunk <stephen@sprunk.org> - 2011-06-27 12:09 -0500
Re: References in C pacman@kosh.dhis.org (Alan Curry) - 2011-06-27 22:16 +0000
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-27 11:57 -0400
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Re: References in C Ike Naar <ike@iceland.freeshell.org> - 2011-06-27 07:05 +0000
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Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-26 18:57 -0500
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-26 19:21 -0700
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Re: References in C pacman@kosh.dhis.org (Alan Curry) - 2011-06-27 23:15 +0000
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Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-06-29 17:46 +0000
Re: References in C Dr Nick <3-nospam@temporary-address.org.uk> - 2011-06-29 20:23 +0100
Re: References in C pacman@kosh.dhis.org (Alan Curry) - 2011-06-29 22:35 +0000
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-29 16:52 -0700
Re: References in C Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-03 01:31 +0300
Re: References in C Chad <cdalten@gmail.com> - 2011-07-02 17:20 -0700
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-29 18:54 -0500
Re: References in C Michael Press <rubrum@pacbell.net> - 2011-06-30 10:32 -0700
Re: References in C "io_x" <a@b.c.invalid> - 2011-07-01 10:19 +0200
Re: References in C pacman@kosh.dhis.org (Alan Curry) - 2011-07-01 19:21 +0000
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-07-01 12:31 -0700
Re: References in C pacman@kosh.dhis.org (Alan Curry) - 2011-07-01 19:32 +0000
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-07-01 13:05 -0700
Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-07-01 23:58 +0000
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Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-07-01 15:57 -0500
Re: References in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-03 14:54 -0700
Re: References in C Michael Press <rubrum@pacbell.net> - 2011-07-03 20:29 -0700
Re: References in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-04 16:05 -0700
Re: References in C Michael Press <rubrum@pacbell.net> - 2011-07-05 08:32 -0700
Re: References in C Lowell Gilbert <lgusenet@be-well.ilk.org> - 2011-07-05 15:34 -0400
Re: References in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-06 15:30 -0700
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Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-27 09:02 -0400
Re: References in C "Joel C. Salomon" <joelcsalomon@gmail.com> - 2011-06-26 18:35 -0400
Re: References in C James Kuyper <jameskuyper@verizon.net> - 2011-06-26 19:11 -0400
Re: References in C "Joel C. Salomon" <joelcsalomon@gmail.com> - 2011-06-28 00:52 -0400
Re: References in C James Kuyper <jameskuyper@verizon.net> - 2011-06-28 07:56 -0400
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Re: References in C gazelle@shell.xmission.com (Kenny McCormack) - 2011-06-24 17:47 +0000
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Re: References in C BGB <cr88192@hotmail.com> - 2011-06-25 16:15 -0700
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Re: References in C Robert Wessel <robertwessel2@yahoo.com> - 2011-06-26 01:31 -0500
Re: References in C BGB <cr88192@hotmail.com> - 2011-06-26 00:03 -0700
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-26 13:54 -0500
Re: References in C luser- -droog <mijoryx@yahoo.com> - 2011-07-07 11:19 -0700
Re: References in C Dr Nick <3-nospam@temporary-address.org.uk> - 2011-06-26 08:15 +0100
Re: References in C Ike Naar <ike@sverige.freeshell.org> - 2011-06-24 16:08 +0000
Re: References in C Tom St Denis <tom@iahu.ca> - 2011-06-24 11:12 -0700
Re: References in C Ike Naar <ike@iceland.freeshell.org> - 2011-06-24 21:42 +0000
Re: References in C Stephen Sprunk <stephen@sprunk.org> - 2011-06-24 11:49 -0500
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-24 13:17 -0700
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-24 16:46 -0400
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-24 14:32 -0700
Re: References in C Gareth Owen <gwowen@gmail.com> - 2011-06-25 09:39 +0100
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-07-04 17:38 -0400
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-06-24 16:33 -0400
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-24 23:04 +0200
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Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-06-29 21:15 +0000
Re: References in C Michael Press <rubrum@pacbell.net> - 2011-06-30 09:26 -0700
Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-06-30 20:55 +0000
Re: References in C Michael Press <rubrum@pacbell.net> - 2011-06-30 16:20 -0700
Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-06-30 23:45 +0000
Re: References in C James Kuyper <jameskuyper@verizon.net> - 2011-07-01 07:58 -0400
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-27 10:43 +0200
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-27 08:32 -0700
Re: References in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-28 11:01 -0700
Re: References in C jacob navia <jacob@spamsink.net> - 2011-06-28 22:17 +0200
Re: References in C Ian Collins <ian-news@hotmail.com> - 2011-06-29 09:05 +1200
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-06-28 22:24 -0700
Re: References in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-29 01:07 -0700
Re: References in C Ian Collins <ian-news@hotmail.com> - 2011-06-29 21:16 +1200
Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-06-29 17:46 +0000
Re: References in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-29 12:19 -0700
Re: References in C sandeep <nospam@nospam.com> - 2011-07-03 20:53 +0000
Re: References in C Chad <cdalten@gmail.com> - 2011-07-03 14:02 -0700
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-07-03 14:33 -0700
Re: References in C jacob navia <jacob@spamsink.net> - 2011-07-04 00:22 +0200
Re: References in C Keith Thompson <kst-u@mib.org> - 2011-07-04 13:41 -0700
Re: References in C gazelle@shell.xmission.com (Kenny McCormack) - 2011-07-04 00:00 +0000
Re: References in C Seebs <usenet-nospam@seebs.net> - 2011-07-04 00:20 +0000
Re: References in C Shao Miller <sha0.miller@gmail.com> - 2011-07-04 17:43 -0400
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