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/*
* Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2013 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.
*
*/
// RefPtr and PassRefPtr are documented at http://webkit.org/coding/RefPtr.html
#ifndef WTF_RefPtr_h
#define WTF_RefPtr_h
#include "wtf/HashTableDeletedValueType.h"
#include "wtf/PassRefPtr.h"
#include "wtf/RawPtr.h"
#include <algorithm>
#include <utility>
namespace WTF {
template <typename T> class PassRefPtr;
template <typename T> class RefPtrValuePeeker;
template <typename T> class RefPtr {
public:
ALWAYS_INLINE RefPtr() : m_ptr(nullptr) {}
ALWAYS_INLINE RefPtr(std::nullptr_t) : m_ptr(nullptr) {}
ALWAYS_INLINE RefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); }
template <typename U> RefPtr(const RawPtr<U>& ptr, EnsurePtrConvertibleArgDecl(U, T)) : m_ptr(ptr.get()) { refIfNotNull(m_ptr); }
ALWAYS_INLINE explicit RefPtr(T& ref) : m_ptr(&ref) { m_ptr->ref(); }
ALWAYS_INLINE RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { refIfNotNull(m_ptr); }
template <typename U> RefPtr(const RefPtr<U>& o, EnsurePtrConvertibleArgDecl(U, T)) : m_ptr(o.get()) { refIfNotNull(m_ptr); }
RefPtr(RefPtr&& o) : m_ptr(o.m_ptr) { o.m_ptr = nullptr; }
// See comments in PassRefPtr.h for an explanation of why this takes a const
// reference.
template <typename U> RefPtr(const PassRefPtr<U>&, EnsurePtrConvertibleArgDecl(U, T));
// Hash table deleted values, which are only constructed and never copied or
// destroyed.
RefPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) {}
bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
ALWAYS_INLINE ~RefPtr() { derefIfNotNull(m_ptr); }
ALWAYS_INLINE T* get() const { return m_ptr; }
void clear();
PassRefPtr<T> release()
{
PassRefPtr<T> tmp = adoptRef(m_ptr);
m_ptr = nullptr;
return tmp;
}
T& operator*() const { return *m_ptr; }
ALWAYS_INLINE T* operator->() const { return m_ptr; }
bool operator!() const { return !m_ptr; }
// This conversion operator allows implicit conversion to bool but not to
// other integer types.
typedef T* (RefPtr::*UnspecifiedBoolType);
operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::m_ptr : 0; }
RefPtr& operator=(RefPtr o) { swap(o); return *this; }
RefPtr& operator=(std::nullptr_t) { clear(); return *this; }
// This is required by HashMap<RefPtr>>.
template <typename U> RefPtr& operator=(RefPtrValuePeeker<U>);
void swap(RefPtr&);
static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
private:
T* m_ptr;
};
template <typename T>
template <typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T))
: m_ptr(o.leakRef())
{
}
template <typename T> inline void RefPtr<T>::clear()
{
T* ptr = m_ptr;
m_ptr = nullptr;
derefIfNotNull(ptr);
}
template <typename T>
template <typename U> inline RefPtr<T>& RefPtr<T>::operator=(RefPtrValuePeeker<U> optr)
{
RefPtr ptr = static_cast<U*>(optr);
swap(ptr);
return *this;
}
template <class T> inline void RefPtr<T>::swap(RefPtr& o)
{
std::swap(m_ptr, o.m_ptr);
}
template <class T> inline void swap(RefPtr<T>& a, RefPtr<T>& b)
{
a.swap(b);
}
template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b)
{
return a.get() == b.get();
}
template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, U* b)
{
return a.get() == b;
}
template <typename T, typename U> inline bool operator==(T* a, const RefPtr<U>& b)
{
return a == b.get();
}
template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b)
{
return a.get() != b.get();
}
template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, U* b)
{
return a.get() != b;
}
template <typename T, typename U> inline bool operator!=(T* a, const RefPtr<U>& b)
{
return a != b.get();
}
template <typename T, typename U> inline RefPtr<T> static_pointer_cast(const RefPtr<U>& p)
{
return RefPtr<T>(static_cast<T*>(p.get()));
}
template <typename T> inline T* getPtr(const RefPtr<T>& p)
{
return p.get();
}
template <typename T> class RefPtrValuePeeker {
public:
ALWAYS_INLINE RefPtrValuePeeker(T* p): m_ptr(p) {}
ALWAYS_INLINE RefPtrValuePeeker(std::nullptr_t): m_ptr(nullptr) {}
template <typename U> RefPtrValuePeeker(const RefPtr<U>& p): m_ptr(p.get()) {}
template <typename U> RefPtrValuePeeker(const PassRefPtr<U>& p): m_ptr(p.get()) {}
ALWAYS_INLINE operator T*() const { return m_ptr; }
private:
T* m_ptr;
};
} // namespace WTF
using WTF::RefPtr;
using WTF::static_pointer_cast;
#endif // WTF_RefPtr_h