Macro time_fn 

macro_rules! time_fn {
    ($func:expr) => { ... };
}

Macro to time a function call and record the result

Examples

let (result, duration) = time_fn!({
    // Some work to time
    std::thread::sleep(std::time::Duration::from_millis(10));
    "done"
});
assert!(duration >= std::time::Duration::from_millis(10));
assert_eq!(result, "done");