window.signal_close.connect(sigc::bind(sigc::mem_fun(this, &DesertPillars::exit), 0));
keyboard.signal_button_press.connect(sigc::bind_return(sigc::mem_fun(this, &DesertPillars::key_press), false));
window.signal_close.connect(sigc::bind(sigc::mem_fun(this, &DesertPillars::exit), 0));
keyboard.signal_button_press.connect(sigc::bind_return(sigc::mem_fun(this, &DesertPillars::key_press), false));