// Swift 2
let triggerTime = (Int64(NSEC_PER_SEC) * 10)
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, triggerTime), dispatch_get_main_queue(), { () -> Void in
    self.functionToCall()
})

// Swift 3
unowned let unownedSelf = self

let deadlineTime = DispatchTime.now() + .seconds(10)
DispatchQueue.main.asyncAfter(deadline: deadlineTime, execute: {
     unownedSelf.functionToCall()
})