> threads.into_iter().for_each(|t| t.join().unwrap()); What a great title for the almost-last section, it made me laugh. When I saw the title of the final sec

> threads.into_iter().for_each(|t| t.join().unwrap()); What a great title for the almost-last section, it made me laugh. When I saw the title of the final section, I fell from my chair: > int atexit(void (*func)(void))