Someone had commented this in a response on the site. macro_rules! max { ($e: expr) => { $e }; ($e: expr, $($rest: tt)*) => { max($e, max!($

Someone had commented this in a response on the site. macro_rules! max { ($e: expr) => { $e }; ($e: expr, $($rest: tt)*) => { max($e, max!($($rest)*)) } }