pub unsafe extern "C" fn mpg123_replace_reader_handle(
mh: *mut mpg123_handle,
r_read: unsafe extern "C" fn(*mut c_void, *mut c_void, size_t) -> ssize_t,
r_lseek: unsafe extern "C" fn(*mut c_void, off_t, c_int) -> off_t,
cleanup: unsafe extern "C" fn(*mut c_void),
) -> c_int