Macro time 

macro_rules! time {
    ($stat:expr, || $block:expr) => { ... };
    ($stat:expr, move || $block:expr) => { ... };
    ($stat:path, || $block:expr) => { ... };
    ($stat:path, move || $block:expr) => { ... };
    ($stat:expr, || $block:expr; $( $key:literal => $value:literal ), *) => { ... };
    ($stat:expr, move || $block:expr; $( $key:literal => $value:literal ), *) => { ... };
    ($stat:path, || $block:expr; $( $key:literal => $value:literal ), *) => { ... };
    ($stat:path, move || $block:expr; $( $key:literal => $value:literal ), *) => { ... };
    ($stat:expr, || $block:expr; $( $key:expr => $value:expr ), *) => { ... };
    ($stat:expr, move || $block:expr; $( $key:expr => $value:expr ), *) => { ... };
    ($stat:path, || $block:expr; $( $key:expr => $value:expr ), *) => { ... };
    ($stat:path, move || $block:expr; $( $key:expr => $value:expr ), *) => { ... };
}

Time a block of code (reports in ms) NOTE: Try to minimise variation in tag values (avoid things like timestamps or ids). See note in lib docs!