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| From | pa@see.signature.invalid (Pierre Asselin) |
|---|---|
| Newsgroups | comp.std.c |
| Subject | Re: Why are VLAs optional in C11? |
| Date | 2012-08-19 02:27 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <k0piu3$qge$1@reader1.panix.com> (permalink) |
| References | (1 earlier) <k0n48g$tsc$1@dont-email.me> <k0n9he$gml$1@speranza.aioe.org> <k0nbeb$ojg$1@dont-email.me> <k0njp8$52i$1@speranza.aioe.org> <k0ogbj$ff0$1@dont-email.me> |
John Nagle <nagle@animats.com> wrote:
> On 8/18/2012 1:29 AM, Alan Curry wrote:
> > [ how to look for VLAs in prototypes ]
> Thanks. Can anyone else try it on large volumes of
> code they have? So far, no one has been able to find even
> one VLA parameter in production code anywhere. I'd really
> like to find at least one.
I don't have to search. I had to write some numerical code at work
two years ago and I used C99 features, VLAs among them, just to
see if they are any good. Work for hire, proprietary, can't show
it, sorry.
The VLAs are *extraordinarily* useful. First as a replacement
for alloca(). Second, to convert between flat and multidimensional
arrays.
float flat[3*nx*ny*nz];
float (*structured)[ny][nz][3]= (void *)flat;
float *other_flat= &structured[0][0][0][0];
That sort of thing. And, as you ask, in function prototypes.
int fou(size_t n, size_t m, float A[/* n */][m]);
(Not a VLA parameter, since there are no array parameters,
but very much a pointer to VLA parameter.)
--
pa at panix dot com
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Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-17 15:42 -0700
Re: Why are VLAs optional in C11? Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-18 01:19 +0200
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-17 16:23 -0700
Re: Why are VLAs optional in C11? Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-18 10:12 +0200
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-17 21:04 -0700
Re: Why are VLAs optional in C11? pacman@kosh.dhis.org (Alan Curry) - 2012-08-18 05:34 +0000
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-17 23:07 -0700
Re: Why are VLAs optional in C11? pacman@kosh.dhis.org (Alan Curry) - 2012-08-18 08:29 +0000
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-18 09:37 -0700
Re: Why are VLAs optional in C11? pa@see.signature.invalid (Pierre Asselin) - 2012-08-19 02:27 +0000
Re: Why are VLAs optional in C11? Ike Naar <ike@sverige.freeshell.org> - 2012-08-18 17:49 +0000
Re: Why are VLAs optional in C11? Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-18 08:32 +0200
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-18 02:50 -0700
Re: Why are VLAs optional in C11? jacob navia <jacob@spamsink.net> - 2012-08-18 14:33 +0200
Re: Why are VLAs optional in C11? Ike Naar <ike@sverige.freeshell.org> - 2012-08-18 13:23 +0000
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-18 13:48 -0700
Re: Why are VLAs optional in C11? jacob navia <jacob@spamsink.net> - 2012-08-18 23:31 +0200
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-18 18:14 -0700
Re: Why are VLAs optional in C11? jacob navia <jacob@spamsink.net> - 2012-08-19 09:38 +0200
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-19 03:07 -0700
Re: Why are VLAs optional in C11? jacob navia <jacob@spamsink.net> - 2012-08-19 12:29 +0200
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-19 10:38 -0700
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-19 13:14 -0700
Re: Why are VLAs optional in C11? Keith Thompson <kst-u@mib.org> - 2012-08-19 13:59 -0700
Re: Why are VLAs optional in C11? Owen Shepherd <nntp@owenshepherd.net> - 2012-08-27 22:17 +0100
Re: Why are VLAs optional in C11? Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-28 00:34 +0200
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-27 19:36 -0700
Re: Why are VLAs optional in C11? James Kuyper <jameskuyper@verizon.net> - 2012-08-27 22:54 -0400
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-27 22:39 -0700
Re: Why are VLAs optional in C11? "pdx_scooter@yahoo.com" <pdx_scooter@yahoo.com> - 2022-10-01 13:15 -0700
Re: Why are VLAs optional in C11? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-10-01 14:33 -0700
Re: Why are VLAs optional in C11? Tomasz Stanislawski <stanislawski.tomasz@googlemail.com> - 2023-01-25 04:21 -0800
Re: Why are VLAs optional in C11? Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-08-17 20:54 -0400
Re: Why are VLAs optional in C11? John Nagle <nagle@animats.com> - 2012-08-17 20:56 -0700
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