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| From | Kaz Kylheku <kaz@kylheku.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: free a pointer and have it point to NULL |
| Date | 2014-04-29 13:57 +0000 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <20140429064354.459@kylheku.com> (permalink) |
| References | (1 earlier) <lny4yxvydz.fsf@nuthaus.mib.org> <ljo1b6$rba$1@news.albasani.net> <87fvkw75h8.fsf@gmail.com> <0.0b3e0de7235790a9eb66.20140429131934BST.87d2g0xr8p.fsf@bsb.me.uk> <pointer-20140429142709@ram.dialup.fu-berlin.de> |
On 2014-04-29, Stefan Ram <ram@zedat.fu-berlin.de> wrote: > Ben Bacarisse <ben.usenet@bsb.me.uk> writes: >>Yes: "The value of a pointer becomes indeterminate when the object it >>points to (or just past) reaches the end of its lifetime." (6.2.4 p2). > > Sometimes, in C there is a irritating distinction some people make > between address values and pointers. Some people say that &x is an > address value, but a pointer is /an object/ storing an address value. > > There is some support in N1570 itself for this: > > »A pointer type describes an object whose value provides > a reference to an entity of the referenced type.« (But does not provide pass-by-reference, haha.) > It says »an object«, not »a value«! It says "object, whose value ..."! C types describe objects: i.e. they specify an in-memory representation that can be broken down into bits and bytes (the quantity of the latter being the "sizeof" that type). C values are manipulated in the data processor such that they are not always objects, but their type specifies details about what they look like when they are stored. The above sentence is primarily concerned with defining "pointer type".
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free a pointer and have it point to NULL G G <gdotone@gmail.com> - 2014-04-22 14:22 -0700
Re: free a pointer and have it point to NULL James Kuyper <jameskuyper@verizon.net> - 2014-04-22 17:32 -0400
Re: free a pointer and have it point to NULL G G <gdotone@gmail.com> - 2014-04-22 14:36 -0700
Re: free a pointer and have it point to NULL Keith Thompson <kst-u@mib.org> - 2014-04-22 14:37 -0700
Re: free a pointer and have it point to NULL Johannes Bauer <dfnsonfsduifb@gmx.de> - 2014-04-29 13:10 +0200
Re: free a pointer and have it point to NULL Richard <rgrdev_@gmail.com> - 2014-04-29 13:14 +0200
Re: free a pointer and have it point to NULL Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-04-29 13:19 +0100
Re: free a pointer and have it point to NULL Kaz Kylheku <kaz@kylheku.com> - 2014-04-29 13:57 +0000
Re: free a pointer and have it point to NULL Kaz Kylheku <kaz@kylheku.com> - 2014-04-29 13:43 +0000
Re: free a pointer and have it point to NULL James Kuyper <jameskuyper@verizon.net> - 2014-04-29 09:59 -0400
Re: free a pointer and have it point to NULL Keith Thompson <kst-u@mib.org> - 2014-04-29 07:58 -0700
Re: free a pointer and have it point to NULL Keith Thompson <kst-u@mib.org> - 2014-04-29 11:50 -0700
Re: free a pointer and have it point to NULL James Kuyper <jameskuyper@verizon.net> - 2014-04-29 15:47 -0400
Re: free a pointer and have it point to NULL James Kuyper <jameskuyper@verizon.net> - 2014-04-29 12:41 -0400
Re: free a pointer and have it point to NULL Robert Wessel <robertwessel2@yahoo.com> - 2014-04-29 13:15 -0500
Re: free a pointer and have it point to NULL glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-04-29 21:29 +0000
Re: free a pointer and have it point to NULL glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-04-29 15:26 +0000
Re: free a pointer and have it point to NULL jt@toerring.de (Jens Thoms Toerring) - 2014-04-22 21:43 +0000
Re: free a pointer and have it point to NULL Keith Thompson <kst-u@mib.org> - 2014-04-22 14:53 -0700
Re: free a pointer and have it point to NULL Öö Tiib <ootiib@hot.ee> - 2014-04-24 00:38 -0700
Re: free a pointer and have it point to NULL James Kuyper <jameskuyper@verizon.net> - 2014-04-24 07:52 -0400
Re: free a pointer and have it point to NULL <william@wilbur.25thandClement.com> - 2014-04-24 16:13 -0700
Re: free a pointer and have it point to NULL Ian Collins <ian-news@hotmail.com> - 2014-04-25 12:02 +1200
Re: free a pointer and have it point to NULL <william@wilbur.25thandClement.com> - 2014-04-24 22:03 -0700
Re: free a pointer and have it point to NULL Ian Collins <ian-news@hotmail.com> - 2014-04-25 17:22 +1200
Re: free a pointer and have it point to NULL <william@wilbur.25thandClement.com> - 2014-04-24 23:00 -0700
Re: free a pointer and have it point to NULL Öö Tiib <ootiib@hot.ee> - 2014-04-27 08:32 -0700
Re: free a pointer and have it point to NULL Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2014-04-22 16:19 -0600
Re: free a pointer and have it point to NULL Kaz Kylheku <kaz@kylheku.com> - 2014-04-22 22:41 +0000
Re: free a pointer and have it point to NULL Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2014-04-22 18:17 -0600
Re: free a pointer and have it point to NULL Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2014-04-24 08:48 -0600
non-NULL pointers which have the value 0 (Was: Re: free a pointer and have it point to NULL) Andrew Cooper <root@127.0.0.1> - 2014-04-23 03:28 +0100
Re: non-NULL pointers which have the value 0 (Was: Re: free a pointer and have it point to NULL) Kaz Kylheku <kaz@kylheku.com> - 2014-04-23 04:37 +0000
Re: non-NULL pointers which have the value 0 glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-04-23 06:14 +0000
Re: free a pointer and have it point to NULL Kaz Kylheku <kaz@kylheku.com> - 2014-04-22 22:18 +0000
Re: free a pointer and have it point to NULL Michael Angelo Ravera <maravera@prodigy.net> - 2014-05-03 01:00 -0700
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