// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//compile-flags: -Z borrowck=mir

#![feature(slice_patterns)]

fn mut_head_tail<'a, A>(v: &'a mut [A]) -> Option<(&'a mut A, &'a mut [A])> {
    match *v {
        [ref mut head, ref mut tail..] => {
            Some((head, tail))
        }
        [] => None
    }
}

fn main() {
    let mut v = [1,2,3,4];
    match mut_head_tail(&mut v) {
        None => {},
        Some((h,t)) => {
            *h = 1000;
            t.reverse();
        }
    }
}