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Groups > comp.lang.c > #27254 > unrolled thread
| Started by | gus gassmann <gus@nospam.com> |
|---|---|
| First post | 2012-10-17 06:49 -0300 |
| Last post | 2012-10-19 07:37 -0400 |
| Articles | 6 on this page of 126 — 28 participants |
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C/C++ question about dynamic "static struct" gus gassmann <gus@nospam.com> - 2012-10-17 06:49 -0300
Re: C/C++ question about dynamic "static struct" Noob <root@127.0.0.1> - 2012-10-17 13:08 +0200
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-17 08:19 -0400
Re: C/C++ question about dynamic "static struct" Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-10-17 15:19 +0000
Re: C/C++ question about dynamic "static struct" gus gassmann <gus@nospam.com> - 2012-10-17 18:47 -0300
Re: C/C++ question about dynamic "static struct" Ike Naar <ike@iceland.freeshell.org> - 2012-10-17 22:46 +0000
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-18 07:13 +0000
Re: C/C++ question about dynamic "static struct" Ike Naar <ike@sverige.freeshell.org> - 2012-10-18 22:45 +0000
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-17 18:58 -0400
Re: C/C++ question about dynamic "static struct" Stuart <DerTopper@web.de> - 2012-10-18 09:55 +0200
Re: C/C++ question about dynamic "static struct" jacob navia <jacob@spamsink.net> - 2012-10-18 10:13 +0200
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-18 08:23 +0000
Re: C/C++ question about dynamic "static struct" jacob navia <jacob@spamsink.net> - 2012-10-18 11:17 +0200
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-18 23:37 +1300
Re: C/C++ question about dynamic "static struct" Rui Maciel <rui.maciel@gmail.com> - 2012-10-18 15:35 +0100
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-18 21:45 +1300
Re: C/C++ question about dynamic "static struct" Rui Maciel <rui.maciel@gmail.com> - 2012-10-18 15:03 +0100
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-18 07:18 -0400
Re: C/C++ question about dynamic "static struct" Stuart <DerTopper@web.de> - 2012-10-18 17:43 +0200
Re: C/C++ question about dynamic "static struct" William Ahern <william@wilbur.25thandClement.com> - 2012-10-18 13:52 -0700
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-19 21:34 +1300
Re: C/C++ question about dynamic "static struct" Stuart <DerTopper@web.de> - 2012-10-19 11:03 +0200
Re: C/C++ question about dynamic "static struct" "BartC" <bc@freeuk.com> - 2012-10-20 14:03 +0100
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-19 09:27 +0000
Re: C/C++ question about dynamic "static struct" Stuart <DerTopper@web.de> - 2012-10-19 13:43 +0200
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-19 12:46 +0000
Re: C/C++ question about dynamic "static struct" ImpalerCore <jadill33@gmail.com> - 2012-10-19 10:14 -0700
Re: C/C++ question about dynamic "static struct" Paavo Helde <myfirstname@osa.pri.ee> - 2012-10-19 14:53 -0500
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-19 21:22 +0000
Re: C/C++ question about dynamic "static struct" William Ahern <william@wilbur.25thandClement.com> - 2012-10-19 11:21 -0700
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-19 21:29 +0000
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-19 18:53 -0400
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-20 12:13 +1300
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-20 05:55 +0000
Re: C/C++ question about dynamic "static struct" Stuart <DerTopper@web.de> - 2012-10-20 13:24 +0200
Re: C/C++ question about dynamic "static struct" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-10-20 12:54 +0100
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-20 06:45 -0700
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-21 09:20 +1300
Re: C/C++ question about dynamic "static struct" Dombo <dombo@disposable.invalid> - 2012-10-20 22:28 +0200
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:05 +0000
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 02:23 -0500
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:32 +0000
Re: C/C++ question about dynamic "static struct" "BartC" <bc@freeuk.com> - 2012-10-21 11:56 +0100
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 12:54 -0500
Re: C/C++ question about dynamic "static struct" ptyxs <kerloch@gmail.com> - 2012-10-22 13:43 +0200
Re: C/C++ question about dynamic "static struct" gwowen <gwowen@gmail.com> - 2012-10-26 03:37 -0700
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-26 07:33 -0500
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:14 -0700
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:08 -0700
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-20 13:44 -0500
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-21 09:09 +1300
Re: C/C++ question about dynamic "static struct" Dombo <dombo@disposable.invalid> - 2012-10-20 22:31 +0200
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 02:11 -0500
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-21 20:28 +1300
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:40 +0000
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 13:31 -0500
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-22 08:41 +1300
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 16:24 -0500
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-22 07:52 +0000
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-22 14:02 -0500
Re: C/C++ question about dynamic "static struct" gwowen <gwowen@gmail.com> - 2012-10-26 03:41 -0700
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-26 07:53 -0500
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-26 09:51 -0400
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-26 13:48 -0400
Re: C/C++ question about dynamic "static struct" ImpalerCore <jadill33@gmail.com> - 2012-10-26 07:35 -0700
Re: C/C++ question about dynamic "static struct" Paavo Helde <myfirstname@osa.pri.ee> - 2012-10-26 18:42 -0500
Re: C/C++ question about dynamic "static struct" ImpalerCore <jadill33@gmail.com> - 2012-10-27 04:21 -0700
Re: C/C++ question about dynamic "static struct" Paavo Helde <myfirstname@osa.pri.ee> - 2012-10-27 08:06 -0500
Re: C/C++ question about dynamic "static struct" ImpalerCore <jadill33@gmail.com> - 2012-10-27 06:50 -0700
Re: C/C++ question about dynamic "static struct" Paavo Helde <myfirstname@osa.pri.ee> - 2012-10-27 11:13 -0500
Re: C/C++ question about dynamic "static struct" ImpalerCore <jadill33@gmail.com> - 2012-10-27 12:02 -0700
Re: C/C++ question about dynamic "static struct" Paavo Helde <myfirstname@osa.pri.ee> - 2012-10-27 15:46 -0500
Re: C/C++ question about dynamic "static struct" ImpalerCore <jadill33@gmail.com> - 2012-10-27 20:24 -0700
Re: C/C++ question about dynamic "static struct" Dombo <dombo@disposable.invalid> - 2012-10-27 20:11 +0200
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:43 -0700
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-27 13:52 -0500
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-27 14:40 -0500
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:35 -0700
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-27 14:24 -0500
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:36 -0700
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:08 +0000
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 02:51 -0500
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-21 21:09 +1300
Re: C/C++ question about dynamic "static struct" Rui Maciel <rui.maciel@gmail.com> - 2012-10-21 12:16 +0100
Re: C/C++ question about dynamic "static struct" Rui Maciel <rui.maciel@gmail.com> - 2012-10-21 11:55 +0100
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:30 -0700
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-20 09:06 -0400
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:11 +0000
Re: C/C++ question about dynamic "static struct" Rui Maciel <rui.maciel@gmail.com> - 2012-10-21 11:56 +0100
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-21 07:43 -0400
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-22 08:13 +0000
Re: C/C++ question about dynamic "static struct" Steve Thompson <stevet810@gmail.com> - 2012-10-22 15:08 +0000
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-22 14:42 -0400
Re: C/C++ question about dynamic "static struct" Rui Maciel <rui.maciel@gmail.com> - 2012-10-21 10:12 +0100
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-20 13:24 -0500
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:16 +0000
Re: C/C++ question about dynamic "static struct" Les Cargill <lcargill99@comcast.com> - 2012-10-21 13:57 -0500
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-22 08:17 +0000
Re: C/C++ question about dynamic "static struct" Fritz Wuehler <fritz@spamexpire-201210.rodent.frell.theremailer.net> - 2012-10-20 22:41 +0200
Re: C/C++ question about dynamic "static struct" Dombo <dombo@disposable.invalid> - 2012-10-21 01:04 +0200
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:23 +0000
Re: C/C++ question about dynamic "static struct" Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-10-21 19:33 +0000
Re: C/C++ question about dynamic "static struct" Greg Martin <greg@softsprocket.com> - 2012-10-21 13:20 -0700
Re: C/C++ question about dynamic "static struct" Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-10-23 15:44 +0000
Re: C/C++ question about dynamic "static struct" Dombo <dombo@disposable.invalid> - 2012-10-23 20:01 +0200
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-20 06:13 -0700
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-21 07:25 +0000
Re: C/C++ question about dynamic "static struct" Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-10-27 05:54 -0700
Re: C/C++ question about dynamic "static struct" Old Wolf <oldwolf@inspire.net.nz> - 2012-11-11 14:58 -0800
Re: C/C++ question about dynamic "static struct" gof@somewhere.invalid (Adam Wysocki) - 2012-11-12 10:33 +0000
Re: C/C++ question about dynamic "static struct" Ian Collins <ian-news@hotmail.com> - 2012-10-18 12:19 +1300
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-18 07:06 +0000
Re: C/C++ question about dynamic "static struct" Noob <root@127.0.0.1> - 2012-10-18 11:36 +0200
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-19 09:28 +0000
Re: C/C++ question about dynamic "static struct" Noob <root@127.0.0.1> - 2012-10-19 12:07 +0200
Re: C/C++ question about dynamic "static struct" gus gassmann <gus@nospam.com> - 2012-10-19 08:03 -0300
Re: C/C++ question about dynamic "static struct" Fritz Wuehler <fritz@spamexpire-201210.rodent.frell.theremailer.net> - 2012-10-20 07:14 +0200
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-19 06:58 -0400
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-17 08:29 -0400
Re: C/C++ question about dynamic "static struct" Richard Damon <news.x.richarddamon@xoxy.net> - 2012-10-17 08:35 -0400
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-17 08:49 -0400
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-18 07:10 +0000
Re: C/C++ question about dynamic "static struct" Keith Thompson <kst-u@mib.org> - 2012-10-18 12:11 -0700
Re: C/C++ question about dynamic "static struct" Juha Nieminen <nospam@thanks.invalid> - 2012-10-19 09:30 +0000
Re: C/C++ question about dynamic "static struct" Keith Thompson <kst-u@mib.org> - 2012-10-19 03:05 -0700
Re: C/C++ question about dynamic "static struct" James Kuyper <jameskuyper@verizon.net> - 2012-10-19 07:37 -0400
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| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Date | 2012-10-17 08:49 -0400 |
| Message-ID | <k5m9hm$mq2$1@dont-email.me> |
| In reply to | #27262 |
On 10/17/2012 08:35 AM, Richard Damon wrote: > On 10/17/12 5:49 AM, gus gassmann wrote: ... > If its size is not know at compile time, then its memory allocation must > be dynamic. (In C99, but not C++ except as an extension, it could also > be of storage type auto). Use of the 'auto' keyword is completely unnecessary in C, because it can only be used in contexts where the object would have automatic storage duration whether or not you used that keyword. In C++ the 'auto' keyword cannot be used for this purpose, because it has been given a different, much more useful meaning. However, automatic storage duration is the default for objects declared with block scope in both C and C++. -- James Kuyper
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| From | Juha Nieminen <nospam@thanks.invalid> |
|---|---|
| Date | 2012-10-18 07:10 +0000 |
| Message-ID | <k5oa1d$i1t$2@speranza.aioe.org> |
| In reply to | #27262 |
In comp.lang.c++ Richard Damon <news.x.richarddamon@xoxy.net> wrote: > If its size is not know at compile time, then its memory allocation must > be dynamic. (In C99, but not C++ except as an extension, it could also > be of storage type auto). I think you are confusing variable-length arrays (in C) with the keyword 'auto', which has absolutely nothing to do with that (in either language). (Btw, and I'm not talking about you specifically, but is it just me or are most of the answers to the OP's question given in this thread unusually vague, incorrect and outright incompetent?)
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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Date | 2012-10-18 12:11 -0700 |
| Message-ID | <lnvce7ioin.fsf@nuthaus.mib.org> |
| In reply to | #27299 |
Juha Nieminen <nospam@thanks.invalid> writes:
> In comp.lang.c++ Richard Damon <news.x.richarddamon@xoxy.net> wrote:
>> If its size is not know at compile time, then its memory allocation must
>> be dynamic. (In C99, but not C++ except as an extension, it could also
>> be of storage type auto).
>
> I think you are confusing variable-length arrays (in C) with the keyword
> 'auto', which has absolutely nothing to do with that (in either language).
Richard didn't mention the "auto" *keyword*. I think his point is
that a VLA must have automatic storage duration ("storage type auto"
was not the best way to phrase that).
Which is true for *identifiers* defined as VLAs, but not for all VLAs:
int x = /* whatever */;
int y = /* whatever */;
typedef double vla[x][y];
vla *ptr = malloc(sizeof *ptr);
if (ptr == NULL) {
/* allocation failed */
}
This lets you allocate a VLA on the heap. It has the advantage that
you can easily use array notation to access elements of the VLA:
(*ptr)[i][j]
without having to manage arrays of pointers, and you can test
whether the allocation succeeded.
(You can't do this in C++, but the standard library provides ways to do
similar things.)
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Will write code for food.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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| From | Juha Nieminen <nospam@thanks.invalid> |
|---|---|
| Date | 2012-10-19 09:30 +0000 |
| Message-ID | <k5r6ka$at5$3@speranza.aioe.org> |
| In reply to | #27315 |
In comp.lang.c++ Keith Thompson <kst-u@mib.org> wrote:
> Which is true for *identifiers* defined as VLAs, but not for all VLAs:
>
> int x = /* whatever */;
> int y = /* whatever */;
> typedef double vla[x][y];
> vla *ptr = malloc(sizeof *ptr);
> if (ptr == NULL) {
> /* allocation failed */
> }
I don't think dynamically allocated arrays with malloc() are called
"variable length arrays". That term is quite specific and refers to
the new C99 feature where stack-allocated arrays do not need to have
a compile-time constant size.
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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Date | 2012-10-19 03:05 -0700 |
| Message-ID | <lnd30eixp6.fsf@nuthaus.mib.org> |
| In reply to | #27342 |
Juha Nieminen <nospam@thanks.invalid> writes:
> In comp.lang.c++ Keith Thompson <kst-u@mib.org> wrote:
>> Which is true for *identifiers* defined as VLAs, but not for all VLAs:
>>
>> int x = /* whatever */;
>> int y = /* whatever */;
>> typedef double vla[x][y];
>> vla *ptr = malloc(sizeof *ptr);
>> if (ptr == NULL) {
>> /* allocation failed */
>> }
>
> I don't think dynamically allocated arrays with malloc() are called
> "variable length arrays". That term is quite specific and refers to
> the new C99 feature where stack-allocated arrays do not need to have
> a compile-time constant size.
The type "vla" is a variable-length array type. I happened to
allocate an object of that type via malloc(), rather than as a
declared object at block scope. The type meets the definition of
"variable length array" in N1370 6.7.6.2p4.
Not all arrays allocated with malloc() are VLAs, only those of some
VLA type:
typedef double not_a_vla[100];
not_a_vla *ptr = malloc(sizeof *not_a_vla);
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Will write code for food.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Date | 2012-10-19 07:37 -0400 |
| Message-ID | <k5re1c$d5c$1@dont-email.me> |
| In reply to | #27342 |
On 10/19/2012 05:30 AM, Juha Nieminen wrote:
> In comp.lang.c++ Keith Thompson <kst-u@mib.org> wrote:
>> Which is true for *identifiers* defined as VLAs, but not for all VLAs:
>>
>> int x = /* whatever */;
>> int y = /* whatever */;
>> typedef double vla[x][y];
>> vla *ptr = malloc(sizeof *ptr);
>> if (ptr == NULL) {
>> /* allocation failed */
>> }
>
> I don't think dynamically allocated arrays with malloc() are called
> "variable length arrays". That term is quite specific and refers to
> the new C99 feature where stack-allocated arrays do not need to have
> a compile-time constant size.
<side_issue>The C standard doesn't talk about "stack-allocated". The
closest it comes is the term "automatic storage duration". I'll assume
that's what you're talking about. While the rules governing the
lifetimes of objects with automatic storage duration allow, and even
encourage, implementation using stack-like semantics, it's not mandatory
that they be allocated from the actual hardware stack (if there even is
one). For example, some real-world implementations implement those
semantics using activation records rather than a hardware
stack.</side_issue>
"... If an identifier is declared to be an object with static or thread
storage duration, it shall not have a variable length array type. ..."
(6.7.6.2p2). Only two of the four storage durations are prohibited by
that clause; both automatic and allocated storage durations are allowed.
"... If the size is * instead of being an expression, the array type is
a variable length array ... If the size is an integer constant
expression and the element type has a known constant size, the array
type is not a variable length array type; otherwise, the array type is a
variable length array type. ..." (6.7.6.2p4) The first and third
occurrences of "variable length array" in that citation are italicized,
indicating that those sentences together constitute the definition of
the term.
The type of *ptr is an array with a size of x, which is neither '*' nor
an integer constant expression. That alone would be enough to give *ptr
a variable length array type. However, the element type of that array is
also double[y], which does not have a known constant size, which would
therefore also be sufficient to make it a variable length array type.
ptr itself does NOT have a VLA type, it only points at one. It does,
however, have a variably modified (VM) type. There are no restrictions
on the storage duration of VM types, only of VLA types.
--
James Kuyper
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