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| From | Melzzzzz <mel@zzzzz.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: "Death To C" |
| Date | 2015-05-05 00:06 +0200 |
| Organization | albasani.net |
| Message-ID | <20150505000636.53ef225f@maxa-pc> (permalink) |
| References | <mi8hvq$p37$1@dont-email.me> <20150504221635.7087171e@maxa-pc> <98c9c53a-f87d-4990-a74c-27582bd0cd3f@googlegroups.com> <mi8mmb$clq$1@dont-email.me> |
On Mon, 04 May 2015 22:02:01 +0100
Bartc <bc@freeuk.com> wrote:
> On 04/05/2015 21:26, Malcolm McLean wrote:
> > On Monday, May 4, 2015 at 9:16:43 PM UTC+1, Melzzzzz wrote:
>
> >> Please compare this elegant C program:
> >> http://benchmarksgame.alioth.debian.org/u64q/program.php?test=nbody&lang=gcc&id=1
> >> with this ugly mess, that Rust is:
> >> http://benchmarksgame.alioth.debian.org/u64q/program.php?test=nbody&lang=rust&id=1
> >>
> > This sort of stuff
> >
> > /// Pop a mutable reference off the head of a slice, mutating the
> > slice to no
> >
> > /// longer contain the mutable reference.
> >
> > fn shift_mut_ref<'a, T>(r: &mut &'a mut [T]) -> Option<&'a mut T> {
> >
> > if r.len() == 0 { return None }
> >
> > let tmp = std::mem::replace(r, &mut []);
> >
> > let (h, t) = tmp.split_at_mut(1);
> >
> > *r = t;
> >
> > Some(&mut h[0])
> >
> > }
> >
> > is unacceptable in a general purpose language.
>
> I completely agree. Even given that I don't know what half that stuff
> means, I don't want to have to write it no matter how good the
> intentions.
This is because Rust doesn't allow two mutable references to same
variable, in this case, array.
You can write it "unsafe" way no problem, just initialize raw pointer
with address of element, but this way is somehow "safe" ;)
What it does is that it splits slice of array into head and tail
replacing argument with tail and returning head. Actually you get two
references to same array anyway ...
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
"Death To C" Lynn McGuire <lmc@winsim.com> - 2015-05-04 14:41 -0500
Re: "Death To C" Melzzzzz <mel@zzzzz.com> - 2015-05-04 22:16 +0200
Re: "Death To C" Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-05-04 13:26 -0700
Re: "Death To C" Melzzzzz <mel@zzzzz.com> - 2015-05-04 22:51 +0200
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-04 22:02 +0100
Re: "Death To C" Melzzzzz <mel@zzzzz.com> - 2015-05-05 00:06 +0200
Re: "Death To C" Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-05-04 13:22 -0700
Re: "Death To C" Melzzzzz <mel@zzzzz.com> - 2015-05-04 22:41 +0200
Re: "Death To C" Robert Wessel <robertwessel2@yahoo.com> - 2015-05-04 20:25 -0500
Bounds checking in C (Was: "Death To C") gazelle@shell.xmission.com (Kenny McCormack) - 2015-05-05 02:15 +0000
Re: Bounds checking in C (Was: "Death To C") BGB <cr88192@hotmail.com> - 2015-05-06 10:23 -0500
Re: "Death To C" Les Cargill <lcargill99@comcast.com> - 2015-05-04 21:36 -0500
Re: "Death To C" Robert Wessel <robertwessel2@yahoo.com> - 2015-05-05 01:01 -0500
Re: "Death To C" Les Cargill <lcargill99@comcast.com> - 2015-05-05 12:23 -0500
Re: "Death To C" CHIN Dihedral <dihedral88888@gmail.com> - 2015-05-05 03:06 -0700
Re: "Death To C" Ian Collins <ian-news@hotmail.com> - 2015-05-05 17:43 +1200
Re: "Death To C" Robert Wessel <robertwessel2@yahoo.com> - 2015-05-05 01:00 -0500
Re: "Death To C" Robert Wessel <robertwessel2@yahoo.com> - 2015-05-05 01:13 -0500
Re: "Death To C" Ian Collins <ian-news@hotmail.com> - 2015-05-05 19:15 +1200
Re: "Death To C" Robert Wessel <robertwessel2@yahoo.com> - 2015-05-05 02:41 -0500
Re: "Death To C" Ian Collins <ian-news@hotmail.com> - 2015-05-05 20:12 +1200
Re: "Death To C" glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-05 06:48 +0000
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-05 10:57 +0100
Re: "Death To C" asetofsymbols@gmail.com - 2015-05-05 16:53 -0700
Re: "Death To C" Nobody <nobody@nowhere.invalid> - 2015-05-06 08:10 +0100
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-06 09:53 +0100
Re: "Death To C" Richard Heathfield <rjh@cpax.org.uk> - 2015-05-06 13:49 +0100
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-06 14:29 +0100
Re: "Death To C" Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-05-06 09:43 -0700
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-06 18:24 +0100
Re: "Death To C" asetofsymbols@gmail.com - 2015-05-08 00:44 -0700
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-08 13:49 +0100
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-04 22:15 +0100
Re: "Death To C" BGB <cr88192@hotmail.com> - 2015-05-08 09:09 -0500
Re: "Death To C" Stephen Sprunk <stephen@sprunk.org> - 2015-05-04 16:18 -0500
Re: "Death To C" Ian Collins <ian-news@hotmail.com> - 2015-05-05 12:49 +1200
Re: "Death To C" raltbos@xs4all.nl (Richard Bos) - 2015-05-08 21:52 +0000
Re: "Death To C" Merikissa <merikissa@no.spam.net> - 2015-05-10 04:04 +0300
Re: "Death To C" "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-05-13 08:11 -0700
Re: "Death To C" David Kleinecke <dkleinecke@gmail.com> - 2015-05-13 10:00 -0700
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-13 18:20 +0100
Re: "Death To C" David Kleinecke <dkleinecke@gmail.com> - 2015-05-14 10:47 -0700
Re: "Death To C" "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-05-14 11:09 -0700
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-15 19:21 +0100
Re: "Death To C" David Kleinecke <dkleinecke@gmail.com> - 2015-05-16 09:10 -0700
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-16 20:45 +0100
Re: "Death To C" David Kleinecke <dkleinecke@gmail.com> - 2015-05-17 09:38 -0700
Re: "Death To C" raltbos@xs4all.nl (Richard Bos) - 2015-05-17 10:47 +0000
Re: "Death To C" Bartc <bc@freeuk.com> - 2015-05-17 12:20 +0100
Re: "Death To C" "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-05-13 10:24 -0700
Re: "Death To C" David Brown <david.brown@hesbynett.no> - 2015-05-13 22:01 +0200
Re: "Death To C" Nobody <nobody@nowhere.invalid> - 2015-05-14 07:48 +0100
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