Arduino sketch that creates a "Swith" class that handles debouncing

SC_Sandbox_Switch-Class

//***************************************************************************************************
//Defeinition of "Switch" class
//Should I change the name to avoid conflict with "switch" logical structure?
//***************************************************************************************************


//The switch
class Switch
{
  public:
    //Constructor, pin defines IO pin and t_bounce defines debouncing time
    Switch(int pin, long t_bounce);

    //steps the Finite State Machine (FSM) of the switch forward one cycle
    void FSM();

    //returns state of switch FSM
    int getState();

    //returns the raw value of the IO pin
    int getValue();

  private:

    //hardware related
    int _pin;

    //used in finite state machine
    int _state;
    int _value;

    //necessary timing variables
    long _t_0;
    long _t_bounce;
    long _t;
};

Switch::Switch(int pin, long t_bounce)
{
  //read out the pin assignment
  _pin = pin;
  pinMode(_pin,INPUT_PULLUP);

  //initialize the FSM
  _state = 0;
  _value = 1;  //pullup resistor used, to value is high when no other connection

  //initialize _t and _t_0, read out debounce time
  _t = millis();
  _t_0 = millis();
  _t_bounce = t_bounce;
}

void Switch::FSM()
{
  _value = digitalRead(_pin);
  
  switch(_state) {  //Finite State Machine, see diagram
    
    case 0:
    if (_value == 0) {
      _state = 1;
    }
    break;

    case 1:
    _t_0 = millis();
    _state = 2;
    break;

    case 2:
    //record current time for comparison
    _t = millis();

    if (_value == 1) { //if the user releases button, go back to start
      _state = 0;
    }
    
    if (_t > (_t_0 + _t_bounce)) {  //if the debounce buffer expires, arm
      _state = 3;
    }
    break;

    case 3:
    if (_value == 1) {
      _state = 4;
    }
    break;

    case 4:
    _state = 0;
    break;
  }
}

int Switch::getState()
{
  return _state;
}

int Switch::getValue()
{
  return _value;
}

//***************************************************************************************************
//Main Arduino Sketch
//***************************************************************************************************

Switch button1(7,10);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

}

void loop() {
  button1.FSM();
  Serial.print("button 1 state  = ");
  Serial.println(button1.getState());
}