Macro bookdata::arrow::row::col_type

macro_rules! col_type {
    ($rs:ident, $pl:ty) => { ... };
    ($rs:ident, $pl:ty, $a:ty, $bld: ty) => { ... };
    ($rs:ty, $pl:ty, $a:ty, $bld: ty, $cast:ident) => { ... };
}