rust - unique vector patterns are no longer supported -

i realize rust in flux, i'm trying learn anyway. i'm trying understand how adapt following example, works 0.9, similar works 0.10:

fn main() {     let argv = std::os::args();      let (first, last) = match argv {         [_, first_arg, .., last_arg] => (first_arg, last_arg),         _ => fail!("error: @ least 2 arguments expected.")     };      println!("the first argument {:s}, \               , last argument {:s}.", first, last);  } 

when build 0.10, following error:

error: couldn't read test.rc: no such file or directory (no such file or directory) orflongpmacx8:rust pohl_longsine$ rustc test.rs test.rs:9:9: 9:37 error: unique vector patterns no longer supported test.rs:9         [_, first_arg, .., last_arg] => (first_arg, last_arg),                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: aborting due previous error 

my question: still possible use pattern matching on argv, different syntax, or using match statement on argv no longer possible @ all? if it's former, have change?

you can still match on slices &[t] , fixed length arrays [t, .. n]. so, in case,

fn main() {     let argv = std::os::args();      let (first, last) = match argv.as_slice() {         [_, ref first_arg, .., ref last_arg] => (first_arg, last_arg),         _ => fail!("error: @ least 2 arguments expected.")     };      println!("the first argument {:s}, \               , last argument {:s}.", *first, *last);  } 

note addition of refs. argv ~[~str], i.e. contents owned strings ~str, move ownership when passed value [_, first_arg, .., last_arg] pattern do. it's illegal move ownership out behind borrowed pointer (like slice &[~str]) pattern illegal. 1 can borrow slice (and other pattern) using ref keyword, making first , last both references of type &~str.

one might wonder why *first , *last dereferences aren't trying move ~str out behind &~str, it's because println! macro expanding &*first , &*last, fine.

(we write => (first_arg.as_slice(), last_arg.as_slice()) borrow 2 &~strs straight string slices &str, means don't need dereference in println!.)