pub type sasl_log_t = Option<unsafe extern "C" fn(context: *mut c_void, level: c_int, message: *const c_char) -> c_int>;
enum sasl_log_t { None, Some(unsafe extern "C" fn(_: *mut c_void, _: i32, _: *const i8) -> i32), }
No value.
Some value of type T.
T