[SuperBK]

You need to add initializations for the pusher and shifter. Those are calls to the constructor of the class. 'DoubleSolenoid:oubleSolenoid()

Robot() :
        driver(0), // Use joystick on port 0.
        // Use double solenoid with Forward Channel of 1 and Reverse of 2.
        shootingArm(1, 2),
		shifter(3,4),
		pusher(5,6)