Source/WebCore/platform/graphics/ColorHash.h

/*
 * Copyright (C) 2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "Color.h"
#include <wtf/HashTraits.h>

namespace WTF {

struct ColorHash {
    static unsigned hash(const WebCore::Color& key) { return key.hash(); }
    static bool equal(const WebCore::Color& a, const WebCore::Color& b) { return a == b; }
    static const bool safeToCompareToEmptyOrDeleted = true;
};

template<> struct DefaultHash<WebCore::Color> : ColorHash { };

template<> struct HashTraits<WebCore::Color> : GenericHashTraits<WebCore::Color> {
    static const bool emptyValueIsZero = false;
    static WebCore::Color emptyValue() { return WebCore::Color(HashTableEmptyValue); }

    static void constructDeletedValue(WebCore::Color& slot) { new (NotNull, &slot) WebCore::Color(HashTableDeletedValue); }
    static bool isDeletedValue(const WebCore::Color& value) { return value.isHashTableDeletedValue(); }
};

} // namespace WTF