How to use class in Arduino

HowToUseClassInArduino.cxx

class Control {
public:
  int pin;

  Control(int pin) : pin(pin) {}
  ~Control() {}

  void pinMode(int mode) {
    ::pinMode(pin, mode);
  }

  int digitalRead() {
    return ::digitalRead(pin);
  }

  void digitalWrite(int value) {
    ::digitalWrite(pin, value);
  }
  
  bool isOn() {
    return digitalRead() == HIGH;
  }
  
  bool isOff() {
    return !isOn();
  }
  
  void beOn() {
    digitalWrite(HIGH);
  }
  
  void beOff() {
    digitalWrite(LOW);
  }
};

void* gButton;
void* gLed;
                      
bool gOldState;
bool gState;

void setupButton() {
  Control* button = new Control(7);
  button->pinMode(INPUT);
  gButton = button;
}

void setupLed() {
  Control* led = new Control(13);
  led->pinMode(OUTPUT);
  gLed = led;
}

void setup() {
  setupButton();
  setupLed();
}

void loop() {
  Control* button = (Control*)gButton;
  Control* led = (Control*)gLed;
  bool val = button->isOn();
  if (val && !gOldState) {
    gState = !gState;
    delay(500);
  }
  gOldState = val;
  if (gState) {
    led->beOn();
  } else {
    led->beOff();
  }
}