Macro typed_array_element

macro_rules! typed_array_element {
    ($t: ident,
     $element: ty,
     $unwrap: ident,
     $length_and_data: ident) => { ... };
    ($t: ident,
     $element: ty,
     $unwrap: ident,
     $length_and_data: ident,
     $create_new: ident,
     $get_data: ident) => { ... };
}