DispatchHelper.swift

struct Dispatch {

    static func onMainQueue(block:()->()) {
        onMainQueueWithDelay(0, block: block)
    }

    static func onMainQueueWithDelay(delay: NSTimeInterval, block:()->()) {
        var queue: dispatch_queue_t = dispatch_get_main_queue()
        onQueue(queue, withDelay: delay, block: block)
    }
    
    static func onQueue(queue: dispatch_queue_t, withDelay delay: NSTimeInterval, block: ()->()) {
        var time: dispatch_time_t = dispatch_time(DISPATCH_TIME_NOW, Int64(delay * Double(NSEC_PER_SEC)))
        dispatch_after(time, queue, block)
    }

}



Dispatch.onMainQueue() {}

Dispatch.onMainQueueWithDelay(1.0) {}

let q = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
Dispatch.onQueue(q, withDelay: 20) {}