// waiting for threads in rust
// this example makes a single thread, but does not wait for it to end
// so some of the actions of the thread are not done.

use std::time::Duration;
use std::thread;


fn main() {
    main1();
}

// this is the usual way to do it -- and really the only way
fn main1() {
    // make a single thread using a no argument function defined right here
    // by rule the thing passed must be a "FnOnce closure". 
    // FnOnce means that the function can be used at most once.
    // So the function cannot be pre-defined using 'fn xxx() ...'
    // Also by rule the function must take no args!
    thread::spawn(|| {
        // all this does is print and sleep 10 times
        for i in 1..10 {
            println!("hi number {} from the spawned thread!", i);
            //thread::sleep(Duration::from_millis(1));
        }
    });

    for i in 1..5 {
        println!("hi number {} from the main thread!", i);
        //thread::sleep(Duration::from_millis(1));
    }
}