Apply clang-format with Chromium-style without column limit.

third_party/WebKit/Source/wtf/HashTraits.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 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_HashTraits_h
 #define WTF_HashTraits_h
 
 #include "wtf/HashFunctions.h"
 #include "wtf/HashTableDeletedValueType.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/TypeTraits.h"
 #include <limits>
-#include <string.h> // For memset.
+#include <string.h>  // For memset.
 #include <utility>
 
 namespace WTF {
 
 class String;
-template <bool isInteger, typename T> struct GenericHashTraitsBase;
-template <typename T> class OwnPtr;
-template <typename T> class PassOwnPtr;
-template <typename T> struct HashTraits;
+template <bool isInteger, typename T>
+struct GenericHashTraitsBase;
+template <typename T>
+class OwnPtr;
+template <typename T>
+class PassOwnPtr;
+template <typename T>
+struct HashTraits;
 
 enum ShouldWeakPointersBeMarkedStrongly {
-    WeakPointersActStrong,
-    WeakPointersActWeak
-};
-
-template <typename T> struct GenericHashTraitsBase<false, T> {
-    // The emptyValueIsZero flag is used to optimize allocation of empty hash
-    // tables with zeroed memory.
-    static const bool emptyValueIsZero = false;
-
-    // The hasIsEmptyValueFunction flag allows the hash table to automatically
-    // generate code to check for the empty value when it can be done with the
-    // equality operator, but allows custom functions for cases like String that
-    // need them.
-    static const bool hasIsEmptyValueFunction = false;
-
-    // The starting table size. Can be overridden when we know beforehand that a
-    // hash table will have at least N entries.
+  WeakPointersActStrong,
+  WeakPointersActWeak
+};
+
+template <typename T>
+struct GenericHashTraitsBase<false, T> {
+  // The emptyValueIsZero flag is used to optimize allocation of empty hash
+  // tables with zeroed memory.
+  static const bool emptyValueIsZero = false;
+
+  // The hasIsEmptyValueFunction flag allows the hash table to automatically
+  // generate code to check for the empty value when it can be done with the
+  // equality operator, but allows custom functions for cases like String that
+  // need them.
+  static const bool hasIsEmptyValueFunction = false;
+
+// The starting table size. Can be overridden when we know beforehand that a
+// hash table will have at least N entries.
 #if defined(MEMORY_SANITIZER_INITIAL_SIZE)
-    static const unsigned minimumTableSize = 1;
+  static const unsigned minimumTableSize = 1;
 #else
-    static const unsigned minimumTableSize = 8;
+  static const unsigned minimumTableSize = 8;
 #endif
 
-    template <typename U = void>
-    struct NeedsTracingLazily {
-        static const bool value = NeedsTracing<T>::value;
-    };
-    static const WeakHandlingFlag weakHandlingFlag = IsWeak<T>::value ? WeakHandlingInCollections : NoWeakHandlingInCollections;
+  template <typename U = void>
+  struct NeedsTracingLazily {
+    static const bool value = NeedsTracing<T>::value;
+  };
+  static const WeakHandlingFlag weakHandlingFlag = IsWeak<T>::value ? WeakHandlingInCollections : NoWeakHandlingInCollections;
 };
 
 // Default integer traits disallow both 0 and -1 as keys (max value instead of
 // -1 for unsigned).
-template <typename T> struct GenericHashTraitsBase<true, T> : GenericHashTraitsBase<false, T> {
-    static const bool emptyValueIsZero = true;
-    static void constructDeletedValue(T& slot, bool) { slot = static_cast<T>(-1); }
-    static bool isDeletedValue(T value) { return value == static_cast<T>(-1); }
-};
-
-template <typename T> struct GenericHashTraits : GenericHashTraitsBase<IsInteger<T>::value, T> {
-    typedef T TraitType;
-    typedef T EmptyValueType;
-
-    static T emptyValue() { return T(); }
-
-    // Type for functions that do not take ownership, such as contains.
-    typedef const T& PeekInType;
-    typedef T* IteratorGetType;
-    typedef const T* IteratorConstGetType;
-    typedef T& IteratorReferenceType;
-    typedef const T& IteratorConstReferenceType;
-    static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
-    static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
-    // Type for functions that take ownership, such as add.
-    // The store function either not be called or called once to store something
-    // passed in.  The value passed to the store function will be PassInType.
-    typedef const T& PassInType;
-    static void store(const T& value, T& storage) { storage = value; }
-
-    // Type for return value of functions that transfer ownership, such as take.
-    typedef T PassOutType;
-    static const T& passOut(const T& value) { return value; }
-
-    // Type for return value of functions that do not transfer ownership, such
-    // as get.
-    // FIXME: We could change this type to const T& for better performance if we
-    // figured out a way to handle the return value from emptyValue, which is a
-    // temporary.
-    typedef T PeekOutType;
-    static const T& peek(const T& value) { return value; }
-};
-
-template <typename T> struct HashTraits : GenericHashTraits<T> { };
-
-template <typename T> struct FloatHashTraits : GenericHashTraits<T> {
-    static T emptyValue() { return std::numeric_limits<T>::infinity(); }
-    static void constructDeletedValue(T& slot, bool) { slot = -std::numeric_limits<T>::infinity(); }
-    static bool isDeletedValue(T value) { return value == -std::numeric_limits<T>::infinity(); }
-};
-
-template <> struct HashTraits<float> : FloatHashTraits<float> { };
-template <> struct HashTraits<double> : FloatHashTraits<double> { };
+template <typename T>
+struct GenericHashTraitsBase<true, T> : GenericHashTraitsBase<false, T> {
+  static const bool emptyValueIsZero = true;
+  static void constructDeletedValue(T& slot, bool) { slot = static_cast<T>(-1); }
+  static bool isDeletedValue(T value) { return value == static_cast<T>(-1); }
+};
+
+template <typename T>
+struct GenericHashTraits : GenericHashTraitsBase<IsInteger<T>::value, T> {
+  typedef T TraitType;
+  typedef T EmptyValueType;
+
+  static T emptyValue() { return T(); }
+
+  // Type for functions that do not take ownership, such as contains.
+  typedef const T& PeekInType;
+  typedef T* IteratorGetType;
+  typedef const T* IteratorConstGetType;
+  typedef T& IteratorReferenceType;
+  typedef const T& IteratorConstReferenceType;
+  static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
+  static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
+  // Type for functions that take ownership, such as add.
+  // The store function either not be called or called once to store something
+  // passed in.  The value passed to the store function will be PassInType.
+  typedef const T& PassInType;
+  static void store(const T& value, T& storage) { storage = value; }
+
+  // Type for return value of functions that transfer ownership, such as take.
+  typedef T PassOutType;
+  static const T& passOut(const T& value) { return value; }
+
+  // Type for return value of functions that do not transfer ownership, such
+  // as get.
+  // FIXME: We could change this type to const T& for better performance if we
+  // figured out a way to handle the return value from emptyValue, which is a
+  // temporary.
+  typedef T PeekOutType;
+  static const T& peek(const T& value) { return value; }
+};
+
+template <typename T>
+struct HashTraits : GenericHashTraits<T> {};
+
+template <typename T>
+struct FloatHashTraits : GenericHashTraits<T> {
+  static T emptyValue() { return std::numeric_limits<T>::infinity(); }
+  static void constructDeletedValue(T& slot, bool) { slot = -std::numeric_limits<T>::infinity(); }
+  static bool isDeletedValue(T value) { return value == -std::numeric_limits<T>::infinity(); }
+};
+
+template <>
+struct HashTraits<float> : FloatHashTraits<float> {};
+template <>
+struct HashTraits<double> : FloatHashTraits<double> {};
 
 // Default unsigned traits disallow both 0 and max as keys -- use these traits
 // to allow zero and disallow max - 1.
-template <typename T> struct UnsignedWithZeroKeyHashTraits : GenericHashTraits<T> {
-    static const bool emptyValueIsZero = false;
-    static T emptyValue() { return std::numeric_limits<T>::max(); }
-    static void constructDeletedValue(T& slot, bool) { slot = std::numeric_limits<T>::max() - 1; }
-    static bool isDeletedValue(T value) { return value == std::numeric_limits<T>::max() - 1; }
-};
-
-template <typename P> struct HashTraits<P*> : GenericHashTraits<P*> {
-    static const bool emptyValueIsZero = true;
-    static void constructDeletedValue(P*& slot, bool) { slot = reinterpret_cast<P*>(-1); }
-    static bool isDeletedValue(P* value) { return value == reinterpret_cast<P*>(-1); }
-};
-
-template <typename T> struct SimpleClassHashTraits : GenericHashTraits<T> {
-    static const bool emptyValueIsZero = true;
-    static void constructDeletedValue(T& slot, bool) { new (NotNull, &slot) T(HashTableDeletedValue); }
-    static bool isDeletedValue(const T& value) { return value.isHashTableDeletedValue(); }
-};
-
-template <typename P> struct HashTraits<OwnPtr<P>> : SimpleClassHashTraits<OwnPtr<P>> {
-    typedef std::nullptr_t EmptyValueType;
-
-    static EmptyValueType emptyValue() { return nullptr; }
-
-    static const bool hasIsEmptyValueFunction = true;
-    static bool isEmptyValue(const OwnPtr<P>& value) { return !value; }
-
-    typedef typename OwnPtr<P>::PtrType PeekInType;
-
-    typedef PassOwnPtr<P> PassInType;
-    static void store(PassOwnPtr<P> value, OwnPtr<P>& storage) { storage = value; }
-
-    typedef PassOwnPtr<P> PassOutType;
-    static PassOwnPtr<P> passOut(OwnPtr<P>& value) { return value.release(); }
-    static PassOwnPtr<P> passOut(std::nullptr_t) { return nullptr; }
-
-    typedef typename OwnPtr<P>::PtrType PeekOutType;
-    static PeekOutType peek(const OwnPtr<P>& value) { return value.get(); }
-    static PeekOutType peek(std::nullptr_t) { return 0; }
-};
-
-template <typename P> struct HashTraits<RefPtr<P>> : SimpleClassHashTraits<RefPtr<P>> {
-    typedef std::nullptr_t EmptyValueType;
-    static EmptyValueType emptyValue() { return nullptr; }
-
-    static const bool hasIsEmptyValueFunction = true;
-    static bool isEmptyValue(const RefPtr<P>& value) { return !value; }
-
-    typedef RefPtrValuePeeker<P> PeekInType;
-    typedef RefPtr<P>* IteratorGetType;
-    typedef const RefPtr<P>* IteratorConstGetType;
-    typedef RefPtr<P>& IteratorReferenceType;
-    typedef const RefPtr<P>& IteratorConstReferenceType;
-    static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
-    static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
-
-    typedef PassRefPtr<P> PassInType;
-    static void store(PassRefPtr<P> value, RefPtr<P>& storage) { storage = value; }
-
-    typedef PassRefPtr<P> PassOutType;
-    static PassOutType passOut(RefPtr<P>& value) { return value.release(); }
-    static PassOutType passOut(std::nullptr_t) { return nullptr; }
-
-    typedef P* PeekOutType;
-    static PeekOutType peek(const RefPtr<P>& value) { return value.get(); }
-    static PeekOutType peek(std::nullptr_t) { return 0; }
-};
-
-template <typename T> struct HashTraits<RawPtr<T>> : HashTraits<T*> { };
-
-template <> struct HashTraits<String> : SimpleClassHashTraits<String> {
-    static const bool hasIsEmptyValueFunction = true;
-    static bool isEmptyValue(const String&);
+template <typename T>
+struct UnsignedWithZeroKeyHashTraits : GenericHashTraits<T> {
+  static const bool emptyValueIsZero = false;
+  static T emptyValue() { return std::numeric_limits<T>::max(); }
+  static void constructDeletedValue(T& slot, bool) { slot = std::numeric_limits<T>::max() - 1; }
+  static bool isDeletedValue(T value) { return value == std::numeric_limits<T>::max() - 1; }
+};
+
+template <typename P>
+struct HashTraits<P*> : GenericHashTraits<P*> {
+  static const bool emptyValueIsZero = true;
+  static void constructDeletedValue(P*& slot, bool) { slot = reinterpret_cast<P*>(-1); }
+  static bool isDeletedValue(P* value) { return value == reinterpret_cast<P*>(-1); }
+};
+
+template <typename T>
+struct SimpleClassHashTraits : GenericHashTraits<T> {
+  static const bool emptyValueIsZero = true;
+  static void constructDeletedValue(T& slot, bool) { new (NotNull, &slot) T(HashTableDeletedValue); }
+  static bool isDeletedValue(const T& value) { return value.isHashTableDeletedValue(); }
+};
+
+template <typename P>
+struct HashTraits<OwnPtr<P>> : SimpleClassHashTraits<OwnPtr<P>> {
+  typedef std::nullptr_t EmptyValueType;
+
+  static EmptyValueType emptyValue() { return nullptr; }
+
+  static const bool hasIsEmptyValueFunction = true;
+  static bool isEmptyValue(const OwnPtr<P>& value) { return !value; }
+
+  typedef typename OwnPtr<P>::PtrType PeekInType;
+
+  typedef PassOwnPtr<P> PassInType;
+  static void store(PassOwnPtr<P> value, OwnPtr<P>& storage) { storage = value; }
+
+  typedef PassOwnPtr<P> PassOutType;
+  static PassOwnPtr<P> passOut(OwnPtr<P>& value) { return value.release(); }
+  static PassOwnPtr<P> passOut(std::nullptr_t) { return nullptr; }
+
+  typedef typename OwnPtr<P>::PtrType PeekOutType;
+  static PeekOutType peek(const OwnPtr<P>& value) { return value.get(); }
+  static PeekOutType peek(std::nullptr_t) { return 0; }
+};
+
+template <typename P>
+struct HashTraits<RefPtr<P>> : SimpleClassHashTraits<RefPtr<P>> {
+  typedef std::nullptr_t EmptyValueType;
+  static EmptyValueType emptyValue() { return nullptr; }
+
+  static const bool hasIsEmptyValueFunction = true;
+  static bool isEmptyValue(const RefPtr<P>& value) { return !value; }
+
+  typedef RefPtrValuePeeker<P> PeekInType;
+  typedef RefPtr<P>* IteratorGetType;
+  typedef const RefPtr<P>* IteratorConstGetType;
+  typedef RefPtr<P>& IteratorReferenceType;
+  typedef const RefPtr<P>& IteratorConstReferenceType;
+  static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
+  static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
+
+  typedef PassRefPtr<P> PassInType;
+  static void store(PassRefPtr<P> value, RefPtr<P>& storage) { storage = value; }
+
+  typedef PassRefPtr<P> PassOutType;
+  static PassOutType passOut(RefPtr<P>& value) { return value.release(); }
+  static PassOutType passOut(std::nullptr_t) { return nullptr; }
+
+  typedef P* PeekOutType;
+  static PeekOutType peek(const RefPtr<P>& value) { return value.get(); }
+  static PeekOutType peek(std::nullptr_t) { return 0; }
+};
+
+template <typename T>
+struct HashTraits<RawPtr<T>> : HashTraits<T*> {};
+
+template <>
+struct HashTraits<String> : SimpleClassHashTraits<String> {
+  static const bool hasIsEmptyValueFunction = true;
+  static bool isEmptyValue(const String&);
 };
 
 // This struct template is an implementation detail of the
 // isHashTraitsEmptyValue function, which selects either the emptyValue function
 // or the isEmptyValue function to check for empty values.
-template <typename Traits, bool hasEmptyValueFunction> struct HashTraitsEmptyValueChecker;
-template <typename Traits> struct HashTraitsEmptyValueChecker<Traits, true> {
-    template <typename T> static bool isEmptyValue(const T& value) { return Traits::isEmptyValue(value); }
-};
-template <typename Traits> struct HashTraitsEmptyValueChecker<Traits, false> {
-    template <typename T> static bool isEmptyValue(const T& value) { return value == Traits::emptyValue(); }
-};
-template <typename Traits, typename T> inline bool isHashTraitsEmptyValue(const T& value)
-{
-    return HashTraitsEmptyValueChecker<Traits, Traits::hasIsEmptyValueFunction>::isEmptyValue(value);
+template <typename Traits, bool hasEmptyValueFunction>
+struct HashTraitsEmptyValueChecker;
+template <typename Traits>
+struct HashTraitsEmptyValueChecker<Traits, true> {
+  template <typename T>
+  static bool isEmptyValue(const T& value) { return Traits::isEmptyValue(value); }
+};
+template <typename Traits>
+struct HashTraitsEmptyValueChecker<Traits, false> {
+  template <typename T>
+  static bool isEmptyValue(const T& value) { return value == Traits::emptyValue(); }
+};
+template <typename Traits, typename T>
+inline bool isHashTraitsEmptyValue(const T& value) {
+  return HashTraitsEmptyValueChecker<Traits, Traits::hasIsEmptyValueFunction>::isEmptyValue(value);
 }
 
 template <typename FirstTraitsArg, typename SecondTraitsArg>
 struct PairHashTraits : GenericHashTraits<std::pair<typename FirstTraitsArg::TraitType, typename SecondTraitsArg::TraitType>> {
-    typedef FirstTraitsArg FirstTraits;
-    typedef SecondTraitsArg SecondTraits;
-    typedef std::pair<typename FirstTraits::TraitType, typename SecondTraits::TraitType> TraitType;
-    typedef std::pair<typename FirstTraits::EmptyValueType, typename SecondTraits::EmptyValueType> EmptyValueType;
-
-    static const bool emptyValueIsZero = FirstTraits::emptyValueIsZero && SecondTraits::emptyValueIsZero;
-    static EmptyValueType emptyValue() { return std::make_pair(FirstTraits::emptyValue(), SecondTraits::emptyValue()); }
-
-    static const unsigned minimumTableSize = FirstTraits::minimumTableSize;
-
-    static void constructDeletedValue(TraitType& slot, bool zeroValue)
-    {
-        FirstTraits::constructDeletedValue(slot.first, zeroValue);
-        // For GC collections the memory for the backing is zeroed when it is
-        // allocated, and the constructors may take advantage of that,
-        // especially if a GC occurs during insertion of an entry into the
-        // table. This slot is being marked deleted, but If the slot is reused
-        // at a later point, the same assumptions around memory zeroing must
-        // hold as they did at the initial allocation.  Therefore we zero the
-        // value part of the slot here for GC collections.
-        if (zeroValue)
-            memset(reinterpret_cast<void*>(&slot.second), 0, sizeof(slot.second));
-    }
-    static bool isDeletedValue(const TraitType& value) { return FirstTraits::isDeletedValue(value.first); }
+  typedef FirstTraitsArg FirstTraits;
+  typedef SecondTraitsArg SecondTraits;
+  typedef std::pair<typename FirstTraits::TraitType, typename SecondTraits::TraitType> TraitType;
+  typedef std::pair<typename FirstTraits::EmptyValueType, typename SecondTraits::EmptyValueType> EmptyValueType;
+
+  static const bool emptyValueIsZero = FirstTraits::emptyValueIsZero && SecondTraits::emptyValueIsZero;
+  static EmptyValueType emptyValue() { return std::make_pair(FirstTraits::emptyValue(), SecondTraits::emptyValue()); }
+
+  static const unsigned minimumTableSize = FirstTraits::minimumTableSize;
+
+  static void constructDeletedValue(TraitType& slot, bool zeroValue) {
+    FirstTraits::constructDeletedValue(slot.first, zeroValue);
+    // For GC collections the memory for the backing is zeroed when it is
+    // allocated, and the constructors may take advantage of that,
+    // especially if a GC occurs during insertion of an entry into the
+    // table. This slot is being marked deleted, but If the slot is reused
+    // at a later point, the same assumptions around memory zeroing must
+    // hold as they did at the initial allocation.  Therefore we zero the
+    // value part of the slot here for GC collections.
+    if (zeroValue)
+      memset(reinterpret_cast<void*>(&slot.second), 0, sizeof(slot.second));
+  }
+  static bool isDeletedValue(const TraitType& value) { return FirstTraits::isDeletedValue(value.first); }
 };
 
 template <typename First, typename Second>
-struct HashTraits<std::pair<First, Second>> : public PairHashTraits<HashTraits<First>, HashTraits<Second>> { };
+struct HashTraits<std::pair<First, Second>> : public PairHashTraits<HashTraits<First>, HashTraits<Second>> {};
 
 template <typename KeyTypeArg, typename ValueTypeArg>
 struct KeyValuePair {
-    typedef KeyTypeArg KeyType;
-
-    KeyValuePair(const KeyTypeArg& _key, const ValueTypeArg& _value)
-        : key(_key)
-        , value(_value)
-    {
-    }
-
-    template <typename OtherKeyType, typename OtherValueType>
-    KeyValuePair(const KeyValuePair<OtherKeyType, OtherValueType>& other)
-        : key(other.key)
-        , value(other.value)
-    {
-    }
-
-    KeyTypeArg key;
-    ValueTypeArg value;
+  typedef KeyTypeArg KeyType;
+
+  KeyValuePair(const KeyTypeArg& _key, const ValueTypeArg& _value)
+      : key(_key), value(_value) {
+  }
+
+  template <typename OtherKeyType, typename OtherValueType>
+  KeyValuePair(const KeyValuePair<OtherKeyType, OtherValueType>& other)
+      : key(other.key), value(other.value) {
+  }
+
+  KeyTypeArg key;
+  ValueTypeArg value;
 };
 
 template <typename KeyTraitsArg, typename ValueTraitsArg>
 struct KeyValuePairHashTraits : GenericHashTraits<KeyValuePair<typename KeyTraitsArg::TraitType, typename ValueTraitsArg::TraitType>> {
-    typedef KeyTraitsArg KeyTraits;
-    typedef ValueTraitsArg ValueTraits;
-    typedef KeyValuePair<typename KeyTraits::TraitType, typename ValueTraits::TraitType> TraitType;
-    typedef KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTraits::EmptyValueType> EmptyValueType;
-
-    static const bool emptyValueIsZero = KeyTraits::emptyValueIsZero && ValueTraits::emptyValueIsZero;
-    static EmptyValueType emptyValue() { return KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTraits::EmptyValueType>(KeyTraits::emptyValue(), ValueTraits::emptyValue()); }
-
-    template <typename U = void>
-    struct NeedsTracingLazily {
-        static const bool value = NeedsTracingTrait<KeyTraits>::value || NeedsTracingTrait<ValueTraits>::value;
-    };
-    static const WeakHandlingFlag weakHandlingFlag = (KeyTraits::weakHandlingFlag == WeakHandlingInCollections || ValueTraits::weakHandlingFlag == WeakHandlingInCollections) ? WeakHandlingInCollections : NoWeakHandlingInCollections;
-
-    static const unsigned minimumTableSize = KeyTraits::minimumTableSize;
-
-    static void constructDeletedValue(TraitType& slot, bool zeroValue)
-    {
-        KeyTraits::constructDeletedValue(slot.key, zeroValue);
-        // See similar code in this file for why we need to do this.
-        if (zeroValue)
-            memset(reinterpret_cast<void*>(&slot.value), 0, sizeof(slot.value));
-    }
-    static bool isDeletedValue(const TraitType& value) { return KeyTraits::isDeletedValue(value.key); }
+  typedef KeyTraitsArg KeyTraits;
+  typedef ValueTraitsArg ValueTraits;
+  typedef KeyValuePair<typename KeyTraits::TraitType, typename ValueTraits::TraitType> TraitType;
+  typedef KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTraits::EmptyValueType> EmptyValueType;
+
+  static const bool emptyValueIsZero = KeyTraits::emptyValueIsZero && ValueTraits::emptyValueIsZero;
+  static EmptyValueType emptyValue() { return KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTraits::EmptyValueType>(KeyTraits::emptyValue(), ValueTraits::emptyValue()); }
+
+  template <typename U = void>
+  struct NeedsTracingLazily {
+    static const bool value = NeedsTracingTrait<KeyTraits>::value || NeedsTracingTrait<ValueTraits>::value;
+  };
+  static const WeakHandlingFlag weakHandlingFlag = (KeyTraits::weakHandlingFlag == WeakHandlingInCollections || ValueTraits::weakHandlingFlag == WeakHandlingInCollections) ? WeakHandlingInCollections : NoWeakHandlingInCollections;
+
+  static const unsigned minimumTableSize = KeyTraits::minimumTableSize;
+
+  static void constructDeletedValue(TraitType& slot, bool zeroValue) {
+    KeyTraits::constructDeletedValue(slot.key, zeroValue);
+    // See similar code in this file for why we need to do this.
+    if (zeroValue)
+      memset(reinterpret_cast<void*>(&slot.value), 0, sizeof(slot.value));
+  }
+  static bool isDeletedValue(const TraitType& value) { return KeyTraits::isDeletedValue(value.key); }
 };
 
 template <typename Key, typename Value>
-struct HashTraits<KeyValuePair<Key, Value>> : public KeyValuePairHashTraits<HashTraits<Key>, HashTraits<Value>> { };
+struct HashTraits<KeyValuePair<Key, Value>> : public KeyValuePairHashTraits<HashTraits<Key>, HashTraits<Value>> {};
 
 template <typename T>
 struct NullableHashTraits : public HashTraits<T> {
-    static const bool emptyValueIsZero = false;
-    static T emptyValue() { return reinterpret_cast<T>(1); }
+  static const bool emptyValueIsZero = false;
+  static T emptyValue() { return reinterpret_cast<T>(1); }
 };
 
 // This is for tracing inside collections that have special support for weak
 // pointers. The trait has a trace method which returns true if there are weak
 // pointers to things that have not (yet) been marked live. Returning true
 // indicates that the entry in the collection may yet be removed by weak
 // handling. Default implementation for non-weak types is to use the regular
 // non-weak TraceTrait. Default implementation for types with weakness is to
 // call traceInCollection on the type's trait.
 template <WeakHandlingFlag weakHandlingFlag, ShouldWeakPointersBeMarkedStrongly strongify, typename T, typename Traits>
 struct TraceInCollectionTrait;
 
-} // namespace WTF
+}  // namespace WTF
 
 using WTF::HashTraits;
 using WTF::PairHashTraits;
 using WTF::NullableHashTraits;
 using WTF::SimpleClassHashTraits;
 
-#endif // WTF_HashTraits_h
+#endif  // WTF_HashTraits_h