title: Alamofire Value of type 'Result<Any, AFError>' has no member 'isSuccess' (Swift 5)
body: <p>I have a simple procedure, which I used in my earlier version (<em>Swift 4</em>). I have now updated to the new version (<em>Swift 5, Alamofire 5.0.0-rc.2</em>), as I am still beginner I got problems with this. Some code parts I could already rewrite. </p>
  
  <pre><code>let headers: HTTPHeaders = [
          "SubscriptionKey": SubscriptionKey,
          "Host": HostName
      ]
  
      AF.request(URL(string: userInfoUrl)!, method: .get, parameters: nil, encoding: JSONEncoding.default, headers: headers)
          .validate()
          .responseJSON { response in
              guard response.result.isSuccess else {
                  log.error("Error requesting user ID: \(String(describing: response.result.error))")
                  completion(false, nil)
                  return
              }
  
              guard let json = response.result.value as? [String: Any], let userId = json["userId"] as? String else {
                  log.error("Malformed result from API call.")
                  completion(false, nil)
                  return
              }
  </code></pre>
  
  <p><strong>response.result.isSuccess</strong> is not possible. How can I reuse this part?</p>
  
  <p>Error: Value of type 'Result' has no member 'isSuccess'</p>
  
  <p>As a possible solution, I will test the above solution.</p>
  
  <pre><code>AF.request(URL(string: userInfoUrl)!, method: .get, parameters: nil, encoding: JSONEncoding.default, headers: headers)
      .validate()
      .responseJSON { response in
          switch response.result{
          case .success(let value):
              //succcess, do anything
  
          case .failure(let error):
              log.error("Error requesting user ID: \(String(describing: response.error))")
              completion(false, nil)
              return
          }
  </code></pre>