Add removeAll method to sets and maps and use them

Source/wtf/HashSet.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  *
  * 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 81 matching lines @@
         // with some other type, to avoid the cost of type conversion if the object is already
         // in the table. HashTranslator must have the following function members:
         //   static unsigned hash(const T&);
         //   static bool equal(const ValueType&, const T&);
         //   static translate(ValueType&, const T&, unsigned hashCode);
         template<typename HashTranslator, typename T> AddResult add(const T&);
 
         void remove(ValuePeekInType);
         void remove(iterator);
         void clear();
+        template<typename Collection>
+        void removeAll(const Collection& other);
 
         static bool isValidValue(ValuePeekInType);
 
         void trace(typename Allocator::Visitor* visitor)
         {
             m_impl.trace(visitor);
         }
 
     private:
         friend void deleteAllValues<>(const HashSet&);
@@ skipping 99 matching lines @@
         remove(find(value));
     }
 
     template<typename T, typename U, typename V, typename W>
     inline void HashSet<T, U, V, W>::clear()
     {
         m_impl.clear();
     }
 
     template<typename T, typename U, typename V, typename W>
+    template<typename Collection>
+    inline void HashSet<T, U, V, W>::removeAll(const Collection& other)
+    {
+        if (other.isEmpty() || isEmpty())
+            return;
+        typedef typename Collection::const_iterator CollectionIterator;
+        CollectionIterator otherEnd(other.end());
+        for (CollectionIterator it(other.begin()); it != otherEnd; ++it)
+            remove(*it);
+    }
+
+    template<typename T, typename U, typename V, typename W>
     inline bool HashSet<T, U, V, W>::isValidValue(ValuePeekInType value)
     {
         if (ValueTraits::isDeletedValue(value))
             return false;
 
         if (HashFunctions::safeToCompareToEmptyOrDeleted) {
             if (value == ValueTraits::emptyValue())
                 return false;
         } else {
             if (isHashTraitsEmptyValue<ValueTraits>(value))
@@ skipping 29 matching lines @@
         iterator end = collection.end();
         for (unsigned i = 0; it != end; ++it, ++i)
             vector[i] = *it;
     }
 
 } // namespace WTF
 
 using WTF::HashSet;
 
 #endif /* WTF_HashSet_h */