title: Null-conditional boolean in if statement
body: <p>I have an <code>event</code> which returns a <code>boolean</code>. To make sure the event is only fired if anyone is listening, i call it using the null-conditional operator (questionmark). 
  However, this means that I have to add the null-conditional operator to the returned boolean as well. And that means that I cannot figure out how to use it in an if-statement afterwards. Does anyone knows how to handle this?</p>
  
  <pre><code>switch (someInt) 
  {
      case 1:
          // Validate if the form is filled correctly.
          // The event returns true if that is the case.
          bool? isValid = ValidateStuff?.Invoke();
  
          if (isValid)
              // If passed validation go to next step in form 
              GoToNextStep?.Invoke();
          break; 
  
      // There are more cases, but you get the point
      (...)
  }
  </code></pre>