Optimization of HashTraits<RefPtr<P> >::emptyValue()

Source/wtf/HashTraits.h

Index: Source/wtf/HashTraits.h
diff --git a/Source/wtf/HashTraits.h b/Source/wtf/HashTraits.h
index 69df8b781a1447b8f1951c7f955e5c0490768d9d..fe4c12f60e6058309c83bbf58c357f92d939ee9c 100644
--- a/Source/wtf/HashTraits.h
+++ b/Source/wtf/HashTraits.h
@@ -138,17 +138,15 @@ namespace WTF {
     };
 
     template<typename P> struct HashTraits<RefPtr<P> > : SimpleClassHashTraits<RefPtr<P> > {
-        static RefPtr<P>& emptyValue()
-        {
-            static RefPtr<P>& null = *(new RefPtr<P>);
-            return null;
-        }
+        static P* emptyValue() { return 0; }
 
         typedef PassRefPtr<P> PassInType;
         static void store(PassRefPtr<P> value, RefPtr<P>& storage) { storage = value; }
 
         typedef PassRefPtr<P> PassOutType;
         static PassRefPtr<P> passOut(RefPtr<P>& value) { return value.release(); }
+        static PassRefPtr<P> passOut(P* value) { return value; }

[eseidel, 2013/05/06 18:38:59]

What does this do?  Is it safe?

+
         // FIXME: We should consider changing PeekType to a raw pointer for better performance,
         // but then callers won't need to call get; doing so will require updating many call sites.
     };