Helpers to make dispach_* code in Swift a bit more concise.

async_helpers.swift

import Foundation

func async(callback:(Void -> Void)) {
    dispatch_async(dispatch_get_main_queue(), { () -> Void in
        callback()
    })
}

func after(delay:Double, closure:Void->Void) {
    dispatch_after(
        dispatch_time(
            DISPATCH_TIME_NOW,
            Int64(delay * Double(NSEC_PER_SEC))
        ),
        dispatch_get_main_queue(), 
        closure
    )
}