WebCore/IntSizeHash.h

   1 /*
   2  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public License
  15  * along with this library; see the file COPYING.LIB.  If not, write to
  16  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA 02110-1301, USA.
  18  *
  19  */
  20 #ifndef IntSizeHash_h
  21 #define IntSizeHash_h
  22
  23 #include "IntSize.h"
  24 #include <wtf/HashMap.h>
  25 #include <wtf/HashSet.h>
  26
  27 using WebCore::IntSize;
  28
  29 namespace WTF {
  30
  31     template<> struct IntHash<IntSize> {
  32         static unsigned hash(const IntSize& key) { return intHash((static_cast<uint64_t>(key.width()) << 32 | key.height())); }
  33         static bool equal(const IntSize& a, const IntSize& b) { return a == b; }
  34         static const bool safeToCompareToEmptyOrDeleted = true;
  35     };
  36     template<> struct DefaultHash<IntSize> { typedef IntHash<IntSize> Hash; };
  37
  38     template<> struct HashTraits<IntSize> : GenericHashTraits<IntSize> {
  39         static const bool emptyValueIsZero = true;
  40         static const bool needsDestruction = false;
  41         static void constructDeletedValue(IntSize& slot) { new (&slot) IntSize(-1, -1); }
  42         static bool isDeletedValue(const IntSize& value) { return value.width() == -1 && value.height() == -1; }
  43     };
  44 } // namespace WTF
  45
  46 #endif