public class Reach {

    private var reachability: SCNetworkReachability!

    func connectionStatus() -> ReachabilityStatus {
        // ...
        return ReachabilityStatus(reachabilityFlags: flags)
    }

    func monitorReachabilityChanges() {
        let host = "google.com"
        var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)
        reachability = SCNetworkReachabilityCreateWithName(nil, host)!

        SCNetworkReachabilitySetCallback(reachability, callback, &context)
        SCNetworkReachabilityScheduleWithRunLoop(reachability, CFRunLoopGetMain(), kCFRunLoopCommonModes)
    }

    func stopMonitoringReachabilityChanges() {
        SCNetworkReachabilityUnscheduleFromRunLoop(reachability, CFRunLoopGetMain(), kCFRunLoopCommonModes)
    }

}

func callback(reachability: SCNetworkReachability, flags: SCNetworkReachabilityFlags, pointer: UnsafeMutablePointer<Void>) {
    let obj = Unmanaged<Reach>.fromOpaque(COpaquePointer(pointer)).takeUnretainedValue() // attempt to create an Unmanaged instance from a null pointer

    let status = ReachabilityStatus(reachabilityFlags: flags)

    NSNotificationCenter.defaultCenter().postNotificationName(ReachabilityStatusChangedNotification, object: nil, userInfo: ["Status": status.description])
}