Accessing front Camera with swift?

I've done some searching and most answers are either in Obj-C or not applicable to this code.

I'm using this guide : http://drivecurrent.com/devops/using-swift-and-avfoundation-to-create-a-custom-camera-view-for-an-ios-app/

and I've got this code from it:

     super.viewWillAppear(animated)

    captureSession = AVCaptureSession()
    captureSession!.sessionPreset = AVCaptureSessionPresetPhoto

    let backCamera = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    let frontCamera = ????

    var error: NSError?
    var input: AVCaptureDeviceInput!
    do {
        input = try AVCaptureDeviceInput(device: backCamera)
    } catch let error1 as NSError {
        error = error1
        input = nil
    }

The back camera is the default but I'm not seeing how to straight up access the front camera in order to let people swap back and forth.

Your currently void frontCamera has a pretty similar behavior to your backCamera one. You need to use devicesWithMediaType(_ mediaType: String!) that allows to store in an array all the devices capable of capturing data of type AVMediaTypeVideo.

let captureDevices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
var frontCamera: AVCaptureDevice

for device in captureDevices {
    let device = element as! AVCaptureDevice
    if device.position == AVCaptureDevicePosition.Front {           
        frontCamera = device
        break
    }
}