You can also make a vector of handles, and use ```.join().unwrap()``` on them. Then you can do what you want with each handle inside. Here is ```main()``` with the handles in a vector:
```rust
fn main() {
let mut handle_vec = vec![]; // each handle will go in here
let my_number = make_arc(0);
for _ in 0..2 {
let my_number_clone = new_clone(&my_number);
let handle = spawn(move || {
for _ in 0..10 {
let mut value_inside = my_number_clone.lock().unwrap();
*value_inside += 1;
}
});
handle_vec.push(handle); // the handle is done, so put it in the vector
}
handle_vec.into_iter().for_each(|handle| handle.join().unwrap()); // Make each one wait