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29 #ifndef AtomicStringHash_h
30 #define AtomicStringHash_h
32 #include "wtf/text/AtomicString.h"
33 #include "wtf/HashTraits.h"
37 struct AtomicStringHash {
38 static unsigned hash(const AtomicString& key)
40 return key.impl()->existingHash();
43 static bool equal(const AtomicString& a, const AtomicString& b)
48 static const bool safeToCompareToEmptyOrDeleted = false;
51 // AtomicStringHash is the default hash for AtomicString
52 template<> struct HashTraits<WTF::AtomicString> : GenericHashTraits<WTF::AtomicString> {
53 // Unlike other types, we can return a const reference for AtomicString's empty value (nullAtom).
54 typedef const WTF::AtomicString& PeekOutType;
56 static const WTF::AtomicString& emptyValue() { return nullAtom; }
57 static PeekOutType peek(const WTF::AtomicString& value) { return value; }
59 static const bool emptyValueIsZero = true;
60 static void constructDeletedValue(WTF::AtomicString& slot, bool) { new (NotNull, &slot) WTF::AtomicString(HashTableDeletedValue); }
61 static bool isDeletedValue(const WTF::AtomicString& slot) { return slot.isHashTableDeletedValue(); }
66 using WTF::AtomicStringHash;