title: Moving code from Xcode 3 to 4 produces error: Cannot declare variable inside @interface or @protocol
body: <p>I am migrating my old iPhone apps from Xcode 3 to Xcode 4.  I receive this error on code which used to build in Xcode 3 -- in fact I wrote it this way on purpose to hide implementation details from other modules.  However, something seems to have changed in  Objective-C.  This code now receives the error</p>
  
  <blockquote>
    <p>Cannot declare variable inside @interface or @protocol.</p>
  </blockquote>
  
  <p>Remember, this is code at the top of the .m file not the .h</p>
  
  <pre><code>@interface VisualViewController ()
  BOOL doReloadPhoto;
  
  + (void)buildVisualEffectInfo;
  
  @property (nonatomic, retain) HandleCheckListSetting *checkListHandler;
  @end
  </code></pre>