namespace { void test() { std::cerr << "DOUBLE CLICK!\n"; } } // Compiles (bind obj takes no arguments) connect_signal_mouse_left_click( find_widget(&window, "new_dir", false), boost::bind(&tfile_dialog::on_dir_create_cmd, this, boost::ref(window))); // Does not compile (func takes no arguments) filelist.connect_signal(test);