pub type sk_BIO_delete_if_func = Option<unsafe extern "C" fn(arg1: *mut BIO, arg2: *mut c_void) -> c_int>;
enum sk_BIO_delete_if_func { None, Some(unsafe extern "C" fn(_: *mut bio_st, _: *mut c_void) -> i32), }
No value.
Some value of type T.
T