Macro advantage::adv_fn

macro_rules! adv_fn {
    {
        $(#[$attr:meta])*
        $vis:vis fn $func_name:ident ( $arg_name:ident : [[$($arg_dim:tt)*]] $( , $extra_arg:ident : $extra_type:ty )* $(,)? ) -> [[$($result_dim:tt)*]] {
            $($tt:tt)*
        }
    } => { ... };
    {
        $(#[$attr:meta])*
        $vis:vis fn $func_name:ident ( $($arg_name:ident : $arg_type:ty $(,)?)* ) $(-> $return_type:ty)? {
            $($tt:tt)*
        }
    } => { ... };
}

Define a function and automatically collect metadata