C++ reference fail

sample.cpp

// Declaration in .ino
PinDef in_pins[__INPUTS_COUNT];
PinDef out_pins[__OUTPUTS_COUNT];
Bounce2::Button db_inputs[__INPUTS_COUNT];

// call:
press->configureInputs(
		db_inputs[LIMIT_STROKE_UP],
		db_inputs[LIMIT_STROKE_DOWN]);

// class / function:
// .h
class PressActuator : public SubsystemBase
{
private:
	Bounce2::Button *_limitSwUp;
	Bounce2::Button *_limitSwDown;
  
public:
	void configureInputs(Bounce2::Button &limitSwUp, Bounce2::Button &limitSwDown);
};

// .cpp
  
void PressActuator::configureInputs(Bounce2::Button& limitSwUp, Bounce2::Button& limitSwDown)
{
	this->_limitSwUp = &limitSwUp;
	this->_limitSwDown = &limitSwDown;
}