pub type deqsc_ft = Option<unsafe extern "C" fn(conjchi: conj_t, chi: *mut f64, psi: *mut f64, is_eq: *mut bool)>;
enum deqsc_ft { None, Some(unsafe extern "C" fn(_: u32, _: *mut f64, _: *mut f64, _: *mut bool)), }
No value.
Some value of type T.
T