// This program spawns multiple threads that each run for at least 250ms, and // each thread returns how much time they took to complete. The program should // wait until all the spawned threads have finished and should collect their // return values into a vector. use std::{ thread, time::{Duration, Instant}, }; fn main() { let mut handles = Vec::new(); for i in 0..10 { let handle = thread::spawn(move || { let start = Instant::now(); thread::sleep(Duration::from_millis(250)); println!("Thread {i} done"); start.elapsed().as_millis() }); handles.push(handle); } let mut results = Vec::new(); for handle in handles { // TODO: Collect the results of all threads into the `results` vector. // Use the `JoinHandle` struct which is returned by `thread::spawn`. } if results.len() != 10 { panic!("Oh no! Some thread isn't done yet!"); } println!(); for (i, result) in results.into_iter().enumerate() { println!("Thread {i} took {result}ms"); } }