Use preprocessor directives to support Swift 2.x
Use preprocessor directives to support Swift 2.x

UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples,UCL-RITS/pi_examples