currentUserRequest.swift

    typealias UserCompletionBlock = (user: User?, error: NSError?) -> ()
    func currentUser(withCompletionBlock completionBlock: UserCompletionBlock) {
        Alamofire.request(Router.CurrentUser)
                 .responseObject(typeOfError: ExampleAPIError.self) { (response: Response<User, NSError>) in
                    switch response.result {
                    case .Success(let user):
                        completionBlock(user: user, error: nil)
                    case .Failure(let error):
                        completionBlock(user: nil, error: error)
                    }
        }
    }