title: Including a constants.h file in Prefix.pch breaks code completion, syntax highlighting
body: <p>My application has many constants (kvo keys, enums, etc.) that are used by almost every class. I have a constants.h file with all of them. I want include this file in the Prefix.pch file as follows:</p>
  
  <pre><code>#ifdef __OBJC__
  #import &lt;UIKit/UIKit.h&gt;
  #import &lt;Foundation/Foundation.h&gt;
  #import "AppConstants.h"
  #endif
  </code></pre>
  
  <p>However, when I include the file in this manner, Xcode 4's syntax highlighting and code completion stops working. If I manually include the constants file in the header file for every class that uses them, and remove the include from the pch file, syntax highlighting and code completion returns. </p>
  
  <p>Is this expected behavior? How can I include a constants file in every file without using the pch file? Is the problem that the "AppConstants.h" file is being included in itself because of the pch file?</p>