Macro dispatch_vector 

macro_rules! dispatch_vector {
    () => { ... };
    ($vis:vis fn $method:ident $tt:tt $(-> $ret:tt)?; $($tail:tt)*) => { ... };
    ($vis:vis fn @$method:ident $tt:tt $(-> $ret:tt)?; $($tail:tt)*) => { ... };
    ($vis:vis fn $method:ident <P: Prime> (p: P $(, $arg:ident: $ty:ty )*) -> (from $fq_name:tt); $($tail:tt)*) => { ... };
    ($vis:vis fn $method:ident <P: Prime> (p: P $(, $arg:ident: $ty:ty )*) -> (from io $fq_name:tt); $($tail:tt)*) => { ... };
}