Question: I am new to swift. I am not able to get a callback to centralManagerDidUpdateState:: w/ following in playground (i.e.: i thought initialization would call back into centralManagerDidUpdateState):

```
import CoreBluetooth
class BTDiscovery:NSObject,
CBCentralManagerDelegate {

    func centralManagerDidUpdateState(central: CBCentralManager!) {
        println("here")
    }
}

var bt = BTDiscovery()

```

---

Is Core Bluetooth supporting in the iOS Swift playground?
I tried this for OSX playground and IOBluetooth. This also didn't work. What am I doing wrong?

Thank you.

Answer: 
You can only use Core Bluetooth on an actual iOS device; it is not supported in the simulator, and by extension, it is not supported in a Playground as this is also executing on your Mac rather than on an iOS device.
Either `XCPSetExecutionShouldContinueIndefinitely` nor `PlaygroundPage.current.needsIndefiniteExecution` will work. 

Please keep in mind CoreBluetooth only works on device. Which means currently it won't work on the Playground.