Showcases how ownership is moved about in Rust...

ownedpointer_error.rs

// You can only have a single owner to a particular memory space.
fn main() {
    let x = box 5i; // create an owned pointer "x" to the value 5i using the "box" keyword
    let y = x; // "y" now owns 5i
    println!("{}", x); // ERROR: "x" is no longer the owner 5i's memory space
}