Function glib_sys::g_ucs4_to_utf8

pub unsafe extern fn g_ucs4_to_utf8(str: *const u32,
                                    len: c_long,
                                    items_read: *mut c_long,
                                    items_written: *mut c_long,
                                    error: *mut *mut GError)
                                    -> *mut c_char