Type Definition openssl_sys::SSL_client_hello_cb_fn
pub type SSL_client_hello_cb_fn = Option<unsafe extern "C" fn(*mut SSL, *mut c_int, *mut c_void) -> c_int>;
The portability is definied by:
#[cfg(ossl111)]
pub type SSL_client_hello_cb_fn = Option<unsafe extern "C" fn(*mut SSL, *mut c_int, *mut c_void) -> c_int>;
#[cfg(ossl111)]