add PoolItem forward decl.

diff --git a/zypp/ResTraits.h b/zypp/ResTraits.h
index 5e00b65..cb72128 100644 (file)
--- a/zypp/ResTraits.h
+++ b/zypp/ResTraits.h
@@ -56,6 +56,9 @@ namespace zypp
   DEFINE_PTR_TYPE( Patch );
   //@}
 
+  /** Frequently associated. */
+  class PoolItem;
+
   /** ResTraits. Defines common types and the ResKind value. */
   template<typename _Res>
     struct ResTraits