A simple Time Tracker in Rust

time_tracker.rs

struct TimeTracker {
    start: Instant,
    name: &'static str,
}

impl TimeTracker {
    fn new(name: &'static str) -> Self {
        TimeTracker {
            start: Instant::now(),
            name,
        }
    }
}
impl Drop for TimeTracker {
    fn drop(&mut self) {
        let elapsed = Instant::now().duration_since(self.start);
        println!("{} took {:?}", self.name, elapsed)
    }
}

mod tests {
    use std::thread;
    use std::time::Duration;
    use crate::TimeTracker;

    #[test]
    fn test_time_tracker() {
        let _time_tracker = TimeTracker::new("time tracker");
        thread::sleep(Duration::from_secs(10))
        // display: time tracker took 10.012828s
    }
}

When the _time_tracker goes out of the scope, the drop function of the TimeTracker instance is launched.