Rust Optimization Opportunity

mem.rs

use std::kinds::marker::NoCopy;

struct WillMove {
  boxed: NoCopy,
  large: [uint, ..100000],
}

/*******************************/
/** VARIANT 1 : with movement **/
/*******************************/

fn show(x: WillMove) {
  println!("The 5th element is {}", x.large[5]);
}

fn main() {
  let x = WillMove {
    boxed: NoCopy,
    large: [20, ..100000],
  };
  show(x);
  // let y = x.large[10]; // uncommenting this line will trigger a compiler error "can't use moved value"
}

/**********************************/
/** VARIANT 2 : with & borrowing **/
/**********************************/

fn show(x: &WillMove) {
  println!("The 5th element is {}", x.large[5]);
}

fn main() {
  let x = WillMove {
    boxed: NoCopy,
    large: [20, ..100000],
  };
  show(&x);
}