title: CGRect unrecognized in subclasses of NSObject
body: <p>Recently I noticed that I cannot use <code>CGRect</code> in any classes I've made that are subclasses of <code>NSObject</code>. I get an error: "Unknown type name 'CGRect'; did you mean 'Rect'?" If I include <code>&lt;UIKit/UIKit.h&gt;</code>, I am able to use <code>CGRect</code> again. However, I noticed that in the classes of my older projects, I am still able to use <code>CGRect</code> without having to import <code>&lt;UIKit/UIKit.h&gt;</code>. I'm curious as to why this occurs.</p>