fn main() {
    let s1 = String::from("hello");
    // Ownership of s1 is moved to the function
    takes_ownership(s1);

    let x = 5;
    // i32 is a Copy type, so x is still
    // valid after the function call
    makes_copy(x);
}

fn takes_ownership(some_string: String) {
    println!("{}", some_string);
} // some_string goes out of scope
  // and the memory is freed

fn makes_copy(some_integer: i32) {
    println!("{}", some_integer);
} // some_integer goes out of scope,
  // but no resources need to be freed