#include <QtCore/qhash.h>
#ifndef QHASH_H
template < typename Key, typename T > class QHash{
   /* Some contents are skipped to improve readability */
   public: class iterator{
      /* ... */
      public: typedef struct std::bidirectional_iterator_tag iterator_category;
      /* ... */
   };
   /* ... */
};
#endif // QHASH_H