Source/WTF/wtf/text/AtomStringHash.h

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#pragma once

#include <wtf/text/AtomString.h>
#include <wtf/HashTraits.h>

namespace WTF {

    struct AtomStringHash {
        static unsigned hash(const AtomString& key)
        {
            return key.impl()->existingHash();
        }

        static bool equal(const AtomString& a, const AtomString& b)
        {
            return a == b;
        }

        static constexpr bool safeToCompareToEmptyOrDeleted = false;
    };

    template<> struct HashTraits<WTF::AtomString> : SimpleClassHashTraits<WTF::AtomString> {
        static constexpr bool hasIsEmptyValueFunction = true;
        static bool isEmptyValue(const AtomString& value)
        {
            return value.isNull();
        }

        static void customDeleteBucket(AtomString& value)
        {
            // See unique_ptr's customDeleteBucket() for an explanation.
            ASSERT(!isDeletedValue(value));
            AtomString valueToBeDestroyed = WTFMove(value);
            constructDeletedValue(value);
        }
    };

}

using WTF::AtomStringHash;