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

Source/wtf/HashTable.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Levin <levin@chromium.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 285 matching lines @@
         swap(a.value, b.value);
     }
 
     template<typename T, bool useSwap> struct Mover;
     template<typename T> struct Mover<T, true> { static void move(T& from, T& to) { hashTableSwap(from, to); } };
     template<typename T> struct Mover<T, false> { static void move(T& from, T& to) { to = from; } };
 
     template<typename HashFunctions> class IdentityHashTranslator {
     public:
         template<typename T> static unsigned hash(const T& key) { return HashFunctions::hash(key); }
-        template<typename T> static bool equal(const T& a, const T& b) { return HashFunctions::equal(a, b); }
+        template<typename T, typename U> static bool equal(const T& a, const U& b) { return HashFunctions::equal(a, b); }
         template<typename T, typename U> static void translate(T& location, const U&, const T& value) { location = value; }
     };
 
     template<typename IteratorType> struct HashTableAddResult {
         HashTableAddResult(IteratorType iter, bool isNewEntry) : iterator(iter), isNewEntry(isNewEntry) { }
         IteratorType iterator;
         bool isNewEntry;
     };
 
     template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
@@ skipping 1100 matching lines @@
     inline bool operator!=(const HashTableIteratorAdapter<T, U>& a, const HashTableConstIteratorAdapter<T, U>& b)
     {
         return a.m_impl != b.m_impl;
     }
 
 } // namespace WTF
 
 #include <wtf/HashIterators.h>
 
 #endif // WTF_HashTable_h