ios - Overriding touchesBegan: Error - method does not override any method from superclass -

i trying override touchesbegan in custom subclass of uitapgesturerecognizer. code below. got here: how accelerate identification of single tap on double tap?. accepted answer, getting error: method not override method superclass. have checked , indeed seems signature touchesbegan. help?

import uikit  class uishorttapgesturerecognizer: uitapgesturerecognizer {     let tapmaxdelay: double = 0.3      override func touchesbegan(touches: set<uitouch>, withevent event: uievent?) {         super.touchesbegan(touches, withevent: event)         delay(tapmaxdelay) {         // enough time has passed , gesture not recognized -> has failed.             if  self.state != uigesturerecognizerstate.ended {                 self.state = uigesturerecognizerstate.failed             }         }     }   } 

the problem stems fact not using xcode 7; syntax in swift 1.2+ not supported xcode version using.

if using xcode version swift version prior 1.2, need change method signature follows:

override func touchesbegan(touches: nsset!, withevent event: uievent?) 

or, upgrade xcode 7.

override func touchesbegan(touches: set<uitouch>, withevent event: uievent?) 

became available since xcode 6.3.