alias.rs

extern crate alias;
use std::cell::Cell;

fn pairwise_diffs(xs: &mut [i32]) {
    let xs: &[Cell<i32>] = alias::slice(xs);
    
    // Iterating & mutating *without* indices!
    for (x, y) in xs.iter().zip(xs[1..].iter()) {
        x.set(y.get() - x.get())
    }

}

fn main() {
    let mut xs = [1, 1, 2, 3, 5, 8, 13, 21, 34];
    pairwise_diffs(&mut xs);
    eprintln!("xs = {:?}", xs);
//  xs = [0, 1, 1, 2, 3, 5, 8, 13, 34]
}