pub type sgetsc_vft = Option<unsafe extern "C" fn(chi: *mut c_void, zeta_r: *mut f64, zeta_i: *mut f64)>;
enum sgetsc_vft { None, Some(unsafe extern "C" fn(_: *mut c_void, _: *mut f64, _: *mut f64)), }
No value.
Some value of type T.
T