Function gio_sys::g_socket_join_multicast_group

pub unsafe extern fn g_socket_join_multicast_group(socket: *mut GSocket,
                                                   group: *mut GInetAddress,
                                                   source_specific: gboolean,
                                                   iface: *const c_char,
                                                   error: *mut *mut GError)
                                                   -> gboolean