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Groups > comp.lang.c++ > #88786
| From | Keith Thompson <Keith.S.Thompson+u@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c++ |
| Subject | Re: A string pointer to a static or dynamic string : how to free the dynamic one ? |
| Date | 2023-01-23 12:34 -0800 |
| Organization | None to speak of |
| Message-ID | <87zga9f0rj.fsf@nosuchdomain.example.com> (permalink) |
| References | (5 earlier) <tqjisu$unr$1@gioia.aioe.org> <sbfzL.383809$iU59.50359@fx14.iad> <tqk620$17ts$1@gioia.aioe.org> <87wn5egtw8.fsf@nosuchdomain.example.com> <tqld98$nc$2@gioia.aioe.org> |
"R.Wieser" <address@not.available> writes:
> "Keith Thompson" <Keith.S.Thompson+u@gmail.com> wrote in message
> news:87wn5egtw8.fsf@nosuchdomain.example.com...
>
>> If I understand you correctly, the two things you're referring to are
>> the pointer *value* and an *object* of pointer type that holds that
>> value.
>
> I do not call it an object, to me its just a variable. Anything beyond that
> (an object wich might contain other properties as well as methods) is (way)
> outside of my scope.
The word "object" is not about object-oriented programming. The C
standard defines an "object" as a "region of data storage in the
execution environment, the contents of which can represent values"; it
doesn't use the term "variable". The C++ standard uses the word "object" in the
same way, though it doesn't have quite the same formal definition.
An "object" is just a variable, except that a variable typically has a
name.
>> There's nothing special about pointers to strings here.
>> The same confusion occurs with, for example, a pointer to an int
>
> Indeed. But if there is one thing I've learned from Usenet it is that you
> need to keep the context to a question simple. Referring to all the other
> adresses and what they point to would just be "muddying the water".
>
>> Usually this isn't a problem. In most contexts, the distinction
>> between a value of some type and an object/variable that holds a
>> value of some type either *isn't important or is sufficiently clear
>> from the context*.
>
> Agreed.
>
> But thats the crux : somethimes I get the distinct feeling that someone is
> talking about the address (pointing to a string or otherwise), but than
> suddenly seems to talk about the variable holding it. :-\
Yes, people are often informal, or even sloppy, about the distinction.
>> For cases where the ambiguity is important, I find it useful
>> to think of the word "pointer" (as well as "array", "integer",
>> etc.) as an adjective rather than a noun. Thus we can refer to a
>> *pointer value*, or a *pointer object", or a *pointer type*, or a
>> *pointer expression*, all of which are clearly distinct concepts.
>
> I think I can translate "pointer value" as to be meaning an address. For
> the others ? I do not have the foggiest I'm afraid.
For example, `int*` and `char*` are pointer types.
A pointer value is the result of evaluating an expression of pointer
type, including an expression that simply yields the value stored in an
object/variable. That value can be the address of an object (or of a
function, but let's set that aside), or it can be a null pointer (there
are other possibilities).
A pointer expression is a chunk of text in a C or C++ program,
interpreted as an expression that, when evaluated, will yield a result
of pointer type.
>> <OT>
>
> Whoooo.... Is that *on*, of *off* topic ? Not that it matters much which
> one though. :-)
"<OT>" means off-topic. I marked the last part of my article that way
because it discusses C, while the topic of this newsgroup is C++, a
distinct language.
You raised the issue of the ambiguity between a "pointer" as a value and
a "pointer" as an object in the context of a "pointer to a string",
which is a C-specific context. I'm trying to steer the discussion in a
direction that applies to both languages. (I might suggest posting to
comp.lang.c, but I'm not sure it would be useful.)
>> For C's definition of a "pointer to a string", I'd say it refers
>> to a *value* of pointer type.
>
> AFAIK most people do not use that phrase but use the (shorthand) "string
> pointer" (with or without the space) instead. But yes, I would also.
Sure, "string pointer" means the same thing as "pointer to a string".
It's slightly informal, but not likely to be ambiguous.
> Though thats the whole problem to me : most people seem to use that "string
> pointer" phrase for the addres (the "value of pointer type") *as well as*
> the variable (or worse : an object) its stored in.
>
> But I think I am going to stop asking. It looks like the destinction
> between the address and what its stored in isn't of much, if any, importance
> to the people here.
Suggestion: Any time you read something specific that you find
confusing, ask about it. That's likely to be a lot easier than trying
to solve the general problem.
People with a lot of experience are likely to write in an informal
shorthand that assumes a similar level of experience in readers. It can
be ambiguous, but the ambiguity can be resolved *if* you have that
experience. If something is genuinely confusing, feel free to keep us
on our toes by asking about it.
--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */
Back to comp.lang.c++ | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-21 15:28 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-21 16:40 +0200
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-21 15:57 +0100
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-21 16:20 +0000
Re: A string pointer to a static or dynamic string : how to free the Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-21 20:15 +0200
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 09:25 +0000
Re: A string pointer to a static or dynamic string : how to free the Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-23 12:11 +0200
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 10:14 +0000
Re: A string pointer to a static or dynamic string : how to free the Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-23 14:14 +0200
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 12:27 +0000
Re: A string pointer to a static or dynamic string : how to free the Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-23 17:56 +0200
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 16:11 +0000
Re: A string pointer to a static or dynamic string : how to free the Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-23 18:58 +0200
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 17:18 +0000
Re: A string pointer to a static or dynamic string : how to free the Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-23 19:49 +0200
Re: A string pointer to a static or dynamic string : how to free the Cholo Lennon <chololennon@hotmail.com> - 2023-01-23 16:44 -0300
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-24 17:05 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-21 19:30 +0100
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 09:30 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-23 13:53 +0100
Re: A string pointer to a static or dynamic string : how to free the scott@slp53.sl.home (Scott Lurndal) - 2023-01-23 14:46 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-23 16:48 +0100
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 16:09 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-23 17:13 +0100
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 16:20 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-23 17:25 +0100
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 16:37 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-23 17:40 +0100
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 17:00 +0000
Re: A string pointer to a static or dynamic string : how to free the Wuns Haerst <Wuns.Haerst@wurstfabrik.at> - 2023-01-23 20:07 +0100
Re: A string pointer to a static or dynamic string : how to free the scott@slp53.sl.home (Scott Lurndal) - 2023-01-23 17:30 +0000
Re: A string pointer to a static or dynamic string : how to free the Bonita Montero <Bonita.Montero@gmail.com> - 2023-01-23 18:39 +0100
Re: A string pointer to a static or dynamic string : how to free the "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2023-01-23 08:40 -0800
Re: A string pointer to a static or dynamic string : how to free the Muttley@dastardlyhq.com - 2023-01-23 17:02 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Juha Nieminen <nospam@thanks.invalid> - 2023-01-23 06:34 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-23 12:49 +0200
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Juha Nieminen <nospam@thanks.invalid> - 2023-01-23 11:51 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-23 04:05 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? wij <wyniijj5@gmail.com> - 2023-01-23 04:45 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Richard Damon <Richard@Damon-Family.org> - 2023-01-21 10:13 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-21 17:53 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-21 08:04 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-21 16:54 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? jak <nospam@please.ty> - 2023-01-22 10:46 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-22 05:20 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? jak <nospam@please.ty> - 2023-01-22 12:17 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Bo Persson <bo@bo-persson.se> - 2023-01-22 12:29 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? jak <nospam@please.ty> - 2023-01-22 13:23 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-22 14:53 +0200
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? jak <nospam@please.ty> - 2023-01-22 19:04 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? jak <nospam@please.ty> - 2023-01-22 19:16 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-23 09:46 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? jak <nospam@please.ty> - 2023-01-23 13:22 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-23 14:42 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-23 06:15 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2023-01-23 08:22 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-23 18:02 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-23 11:14 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2023-01-23 11:38 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-23 13:26 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Richard Damon <Richard@Damon-Family.org> - 2023-01-22 13:24 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-22 11:00 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-22 15:39 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-22 15:28 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 12:27 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Öö Tiib <ootiib@hot.ee> - 2023-01-22 03:42 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-22 15:31 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 15:40 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Richard Damon <Richard@Damon-Family.org> - 2023-01-22 13:24 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-22 11:46 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-23 10:24 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? scott@slp53.sl.home (Scott Lurndal) - 2023-01-23 14:44 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-23 07:34 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-23 18:05 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2023-01-23 09:37 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? scott@slp53.sl.home (Scott Lurndal) - 2023-01-23 17:37 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 21:16 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-22 13:07 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-23 08:33 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-23 04:00 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-23 12:34 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-02 06:43 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2023-02-02 16:36 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-02 17:38 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-22 10:57 -0800
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 21:23 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-22 15:47 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-23 08:04 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-23 04:13 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? David Brown <david.brown@hesbynett.no> - 2023-01-23 10:33 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2023-01-21 18:29 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-21 20:09 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Richard Damon <Richard@Damon-Family.org> - 2023-01-21 16:32 -0500
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 10:52 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2023-01-21 22:10 +0000
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 11:56 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-01-22 14:31 +0200
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? "R.Wieser" <address@not.available> - 2023-01-22 15:57 +0100
Re: A string pointer to a static or dynamic string : how to free the dynamic one ? Juha Nieminen <nospam@thanks.invalid> - 2023-01-23 06:40 +0000
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