title: "Cannot find interface declaration error..." after @class
body: <p>I've run into an Objective-C problem that doesn't seem to make any sense to me.  I am a relatively well-versed ObjC programmer and understand the whole "forward declaration" concept, but this one has me scratching my head.  So here's the deal:</p>
  
  <p>ClassA is a class in my Xcode project that is project-only.
  ClassB is a subclass of ClassA which is public and is imported into my framework's header.</p>
  
  <p>I am getting a "Cannot find interface declaration for 'ClassA', superclass of 'ClassB'..." error when building.  I have already put the <code>@class ClassA;</code> forward declaration in ClassB.h, but that does not seem to solve the problem.  When I change the <code>@class ClassA;</code> to <code>#import ClassA.h</code>, it works fine.  However, since ClassA is project-only, dependent projects cannot build ClassB because it cannot access ClassA's source.</p>
  
  <p>Any help would be appreciated and I hope that makes sense.  Thanks!</p>