swiftでの//extra argument "error" in call について

Question

下記のコードの
withMode: MCSessionSendDataMode.Unreliable, error: &error)
の部分で//Extra argument 'error' in call
というエラーが出てきました。
解決策が知りたいです。
皆様のお力を貸してください。
お願いします。

import UIKit

import MultipeerConnectivity

class ViewController: UIViewController, MCBrowserViewControllerDelegate,
MCSessionDelegate {

let serviceType = "LCOC-Chat"

var browser : MCBrowserViewController!
var assistant : MCAdvertiserAssistant!
var session : MCSession!
var peerID: MCPeerID!

@IBOutlet var chatView: UITextView!
@IBOutlet var messageField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()
    
    self.peerID = MCPeerID(displayName: UIDevice.currentDevice().name)
    self.session = MCSession(peer: peerID)
    self.session.delegate = self
    
    // create the browser viewcontroller with a unique service name
    self.browser = MCBrowserViewController(serviceType:serviceType,
                                           session:self.session)
    
    self.browser.delegate = self;
    
    self.assistant = MCAdvertiserAssistant(serviceType:serviceType,
                                           discoveryInfo:nil, session:self.session)
    
    // tell the assistant to start advertising our fabulous chat
    self.assistant.start()
}

@IBAction func sendChat(sender: UIButton) {
    // Bundle up the text in the message field, and send it off to all
    // connected peers
    
    let msg = self.messageField.text!.dataUsingEncoding(NSUTF8StringEncoding,
                                                       allowLossyConversion: false)
    
    var error : NSError?
    
    self.session.sendData(msg, toPeers: self.session.connectedPeers,
                          withMode: MCSessionSendDataMode.Unreliable, error: &error)
    
    if error != nil {
        print("Error sending data: \(error?.localizedDescription)")
    }
    
    self.updateChat(self.messageField.text!, fromPeer: self.peerID)
    
    self.messageField.text = ""
}

func updateChat(text : String, fromPeer peerID: MCPeerID) {
    // Appends some text to the chat view
    
    // If this peer ID is the local device's peer ID, then show the name
    // as "Me"
    var name : String
    
    switch peerID {
    case self.peerID:
        name = "Me"
    default:
        name = peerID.displayName
    }
    
    // Add the name to the message and display it
    let message = "\(name): \(text)\n"
    self.chatView.text = self.chatView.text + message
    
}

@IBAction func showBrowser(sender: UIButton) {
    // Show the browser view controller
    self.presentViewController(self.browser, animated: true, completion: nil)
}

func browserViewControllerDidFinish(
    browserViewController: MCBrowserViewController)  {
    // Called when the browser view controller is dismissed (ie the Done
    // button was tapped)
    
    self.dismissViewControllerAnimated(true, completion: nil)
}

func browserViewControllerWasCancelled(
    browserViewController: MCBrowserViewController)  {
    // Called when the browser view controller is cancelled
    
    self.dismissViewControllerAnimated(true, completion: nil)
}

func session(session: MCSession, didReceiveData data: NSData,
             fromPeer peerID: MCPeerID)  {
    // Called when a peer sends an NSData to us
    
    // This needs to run on the main queue
    dispatch_async(dispatch_get_main_queue()) {
        
        let msg = String(data: data, encoding: NSUTF8StringEncoding)
        
        self.updateChat(msg!, fromPeer: peerID)
    }
}

// The following methods do nothing, but the MCSessionDelegate protocol
// requires that we implement them.
func session(session: MCSession,
             didStartReceivingResourceWithName resourceName: String,
                                               fromPeer peerID: MCPeerID, withProgress progress: NSProgress)  {
    
    // Called when a peer starts sending a file to us
}

func session(session: MCSession,
             didFinishReceivingResourceWithName resourceName: String,
                                                fromPeer peerID: MCPeerID,
                                                         atURL localURL: NSURL, withError error: NSError?)  {
    // Called when a file has finished transferring from another peer
}

func session(session: MCSession, didReceiveStream stream: NSInputStream,
             withName streamName: String, fromPeer peerID: MCPeerID)  {
    // Called when a peer establishes a stream with us
}

func session(session: MCSession, peer peerID: MCPeerID,
             didChangeState state: MCSessionState)  {
    // Called when a connected peer changes state (for example, goes offline)
    
}

}

Answer 1

Swift2.0からエラー処理の仕方が変更になったので、以下の様に書きなおしてください。
※ 参考: Swift 2.0 エラー処理入門

do {
    
    try self.session.sendData(msg!, toPeers: self.session.connectedPeers, withMode: .Unreliable)
} catch let error as NSError {
    
    print("Error sending data: \(error.description)")
}