use std::time::Instant;

struct Profile {
    lbl: &'static str,
    start: Instant,
}
impl Profile {
    pub fn new(lbl: &'static str) -> Self {
        Profile {
            lbl,
            start: Instant::now(),
        }
    }
}

impl Drop for Profile {
    fn drop(&mut self) {
        println!("{} {:?}", self.lbl, self.start.elapsed());
    }
}

fn main() {
    {
        let _prof = Profile::new("foo");
        println!("work work work");
    }
}