pub type walrcv_send_fn = Option<unsafe extern "C" fn(conn: *mut WalReceiverConn, buffer: *const c_char, nbytes: c_int)>;
enum walrcv_send_fn { None, Some(unsafe extern "C" fn(_: *mut WalReceiverConn, _: *const i8, _: i32)), }
No value.
Some value of type T.
T