Spawn multiple threads

use std::thread;

const NTHREADS: u32 = 6;
// Vector to hold the spawned children.
let mut children = vec![];
for i in 0..NTHREADS {
  // Spin up another thread
  children.push(thread::spawn(move || {
    println!("this is thread number {}", i);
  }));
}
for child in children {
  // Wait for finish to return a result
  let _ = child.join();
}