/*

 * Copyright (C) 2006, 2007, 2008 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_VectorTraits_h

#define WTF_VectorTraits_h

#include "OwnPtr.h"

#include "RefPtr.h"

#include "TypeTraits.h"

#include <utility>

#include <memory>

using std::pair;

namespace WTF {

    template<bool isPod, typename T>

    struct VectorTraitsBase;

    template<typename T>

    struct VectorTraitsBase<false, T>

    {

        static const bool needsDestruction = true;

        static const bool needsInitialization = true;

        static const bool canInitializeWithMemset = false;

        static const bool canMoveWithMemcpy = false;

        static const bool canCopyWithMemcpy = false;

        static const bool canFillWithMemset = false;

        static const bool canCompareWithMemcmp = false;

    };

    template<typename T>

    struct VectorTraitsBase<true, T>

    {

        static const bool needsDestruction = false;

        static const bool needsInitialization = false;

        static const bool canInitializeWithMemset = false;

        static const bool canMoveWithMemcpy = true;

        static const bool canCopyWithMemcpy = true;

        static const bool canFillWithMemset = sizeof(T) == sizeof(char);

        static const bool canCompareWithMemcmp = true;

    };

    template<typename T>

    struct VectorTraits : VectorTraitsBase<IsPod<T>::value, T> { };

    struct SimpleClassVectorTraits

    {

        static const bool needsDestruction = true;

        static const bool needsInitialization = true;

        static const bool canInitializeWithMemset = true;

        static const bool canMoveWithMemcpy = true;

        static const bool canCopyWithMemcpy = false;

        static const bool canFillWithMemset = false;

        static const bool canCompareWithMemcmp = true;

    };

    // we know OwnPtr and RefPtr are simple enough that initializing to 0 and moving with memcpy

    // (and then not destructing the original) will totally work

    template<typename P>

    struct VectorTraits<RefPtr<P> > : SimpleClassVectorTraits { };

    template<typename P>

    struct VectorTraits<OwnPtr<P> > : SimpleClassVectorTraits { };

    template<typename First, typename Second>

    struct VectorTraits<pair<First, Second> >

    {

        typedef VectorTraits<First> FirstTraits;

        typedef VectorTraits<Second> SecondTraits;

        static const bool needsDestruction = FirstTraits::needsDestruction || SecondTraits::needsDestruction;

        static const bool needsInitialization = FirstTraits::needsInitialization || SecondTraits::needsInitialization;

        static const bool canInitializeWithMemset = FirstTraits::canInitializeWithMemset && SecondTraits::canInitializeWithMemset;

        static const bool canMoveWithMemcpy = FirstTraits::canMoveWithMemcpy && SecondTraits::canMoveWithMemcpy;

        static const bool canCopyWithMemcpy = FirstTraits::canCopyWithMemcpy && SecondTraits::canCopyWithMemcpy;

        static const bool canFillWithMemset = false;

        static const bool canCompareWithMemcmp = FirstTraits::canCompareWithMemcmp && SecondTraits::canCompareWithMemcmp;

    };

} // namespace WTF

using WTF::VectorTraits;

using WTF::SimpleClassVectorTraits;

#endif // WTF_VectorTraits_h