title: How to write swift 3 method with throws statement and return value that can be used in Objective C?
body: <p>Below Swift 3 method is translated into Objective C like:</p>
  
  <pre><code>func doSomething(param: String) throws // Swift 3
  
  - (BOOL)doSomething:(NSString * _Nonnull)param error:(NSError * _Nullable * _Nullable)error; // Translated Objective C
  </code></pre>
  
  <p>Then, how can I write a method with both throws and a return type?</p>
  
  <pre><code>func doSomething(param: String) throws -&gt; Int // Swift 3
  
  // Error: Never translated into Objective C
  </code></pre>
  
  <p>I know flow should not be handled by NSError object. It just contains information about an error. And that's why there's a BOOL return type to let us know the invocation is succeeded without any problem.</p>
  
  <p>Then how can I handle a method with both throws statement and return type? Is there a standard way to handle this?</p>
  
  <p>Thank you in advance.</p>