Function melib::gpgme::io::gpgme_register_io_cb

pub unsafe extern "C" fn gpgme_register_io_cb(
    data: *mut c_void, 
    fd: c_int, 
    dir: c_int, 
    fnc: Option<unsafe extern "C" fn(data: *mut c_void, fd: c_int) -> c_uint>, 
    fnc_data: *mut c_void, 
    tag: *mut *mut c_void
) -> c_uint