diff -r 000000000000 -r 4f2f89ce4247 JavaScriptCore/wtf/VectorTraits.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/wtf/VectorTraits.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2006, 2007, 2008 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef WTF_VectorTraits_h
+#define WTF_VectorTraits_h
+
+#include "OwnPtr.h"
+#include "RefPtr.h"
+#include "TypeTraits.h"
+#include <utility>
+#include <memory>
+
+using std::pair;
+
+namespace WTF {
+
+    template<bool isPod, typename T>
+    struct VectorTraitsBase;
+
+    template<typename T>
+    struct VectorTraitsBase<false, T>
+    {
+        static const bool needsDestruction = true;
+        static const bool needsInitialization = true;
+        static const bool canInitializeWithMemset = false;
+        static const bool canMoveWithMemcpy = false;
+        static const bool canCopyWithMemcpy = false;
+        static const bool canFillWithMemset = false;
+        static const bool canCompareWithMemcmp = false;
+    };
+
+    template<typename T>
+    struct VectorTraitsBase<true, T>
+    {
+        static const bool needsDestruction = false;
+        static const bool needsInitialization = false;
+        static const bool canInitializeWithMemset = false;
+        static const bool canMoveWithMemcpy = true;
+        static const bool canCopyWithMemcpy = true;
+        static const bool canFillWithMemset = sizeof(T) == sizeof(char);
+        static const bool canCompareWithMemcmp = true;
+    };
+
+    template<typename T>
+    struct VectorTraits : VectorTraitsBase<IsPod<T>::value, T> { };
+
+    struct SimpleClassVectorTraits
+    {
+        static const bool needsDestruction = true;
+        static const bool needsInitialization = true;
+        static const bool canInitializeWithMemset = true;
+        static const bool canMoveWithMemcpy = true;
+        static const bool canCopyWithMemcpy = false;
+        static const bool canFillWithMemset = false;
+        static const bool canCompareWithMemcmp = true;
+    };
+
+    // we know OwnPtr and RefPtr are simple enough that initializing to 0 and moving with memcpy
+    // (and then not destructing the original) will totally work
+    template<typename P>
+    struct VectorTraits<RefPtr<P> > : SimpleClassVectorTraits { };
+
+    template<typename P>
+    struct VectorTraits<OwnPtr<P> > : SimpleClassVectorTraits { };
+
+    template<typename First, typename Second>
+    struct VectorTraits<pair<First, Second> >
+    {
+        typedef VectorTraits<First> FirstTraits;
+        typedef VectorTraits<Second> SecondTraits;
+
+        static const bool needsDestruction = FirstTraits::needsDestruction || SecondTraits::needsDestruction;
+        static const bool needsInitialization = FirstTraits::needsInitialization || SecondTraits::needsInitialization;
+        static const bool canInitializeWithMemset = FirstTraits::canInitializeWithMemset && SecondTraits::canInitializeWithMemset;
+        static const bool canMoveWithMemcpy = FirstTraits::canMoveWithMemcpy && SecondTraits::canMoveWithMemcpy;
+        static const bool canCopyWithMemcpy = FirstTraits::canCopyWithMemcpy && SecondTraits::canCopyWithMemcpy;
+        static const bool canFillWithMemset = false;
+        static const bool canCompareWithMemcmp = FirstTraits::canCompareWithMemcmp && SecondTraits::canCompareWithMemcmp;
+    };
+
+} // namespace WTF
+
+using WTF::VectorTraits;
+using WTF::SimpleClassVectorTraits;
+
+#endif // WTF_VectorTraits_h