求大神解答一下，success和failure，在我的Xcode6 beta2里一直报错，有以下几个错：

manager.GET(url,    

parameters: params,    

success: { (operation: AFHTTPRequestOperation!,    

responseObject: AnyObject!) in    

println("JSON: " + responseObject.description!)    

self.updateUISuccess(responseObject as NSDictionary!)    

},    

failure: { (operation: AFHTTPRequestOperation!,    

error: NSError!) in    

println("Error: " + error.localizedDescription)    

self.loading.text = "Internet appears down!"    

})    

1. 是不是必须写'in println()' , 否则s会报错

2. success里面写'in println()', 编译器就崩溃了，会有一大片内存的报错信息

3. 要是这样写

success: { (operation: AFHTTPRequestOperation!, responseObject: AnyObject!)

                self.updateUISuccess(responseObject as NSDictionary!)},

failure: { (operation: AFHTTPRequestOperation!,error: NSError!) in println("hello")})

在success的左大括号处报Function produces expected type '((AFHTTPRequestOperation!, AnyObject!) -> Void)!'; did you mean to call it with '()'?

4. 要是这样写

success: { (operation: AFHTTPRequestOperation!, responseObject: AnyObject!)

                             self.updateUISuccess(responseObject as NSDictionary!)},

failure: { (operation: AFHTTPRequestOperation!, error: NSError!)  })

在failure的AFHTTPRequestOperation和NSError都报：Expected member name or constructor call after type name