// Type alias, just gives a new name to the existing type.
// Considered the same type, even using the new name
type Kilometers = i32;

// A type alias is much more useful for a long, complex type
type Thunk = Box<dyn Fn() + Send + 'static>;

fn main() {
    let x: i32 = 5;
    let y: Kilometers = 5;

    println!("x + y = {}", x + y);

    let f: Thunk = Box::new(|| println!("hi"));
    f();
}