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/*
* 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 <wtf/OwnArrayPtr.h>
#include <wtf/OwnPtr.h>
#include <wtf/RefPtr.h>
#include <wtf/TypeTraits.h>
#include <utility>
#include <memory>
using std::pair;
namespace WTF {
class AtomicString;
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 : VectorTraitsBase<false, void>
{
static const bool canInitializeWithMemset = true;
static const bool canMoveWithMemcpy = true;
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 P>
struct VectorTraits<OwnArrayPtr<P> > : SimpleClassVectorTraits { };
template<>
struct VectorTraits<AtomicString> : 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
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