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/*
* Copyright (C) 2013 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 INC. 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 INC. 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.
*/
#ifndef WTF_Ref_h
#define WTF_Ref_h
#include "Noncopyable.h"
namespace WTF {
template<typename T> class PassRef;
template<typename T> class Ref {
WTF_MAKE_NONCOPYABLE(Ref)
public:
Ref(T& object) : m_ptr(&object) { m_ptr->ref(); }
template<typename U> Ref(PassRef<U> reference) : m_ptr(&reference.leakRef()) { }
~Ref() { m_ptr->deref(); }
Ref& operator=(T& object)
{
object.ref();
m_ptr->deref();
m_ptr = &object;
return *this;
}
template<typename U> Ref& operator=(PassRef<U> reference)
{
m_ptr->deref();
m_ptr = &reference.leakRef();
return *this;
}
const T* operator->() const { return m_ptr; }
T* operator->() { return m_ptr; }
const T& get() const { return *m_ptr; }
T& get() { return *m_ptr; }
template<typename U> PassRef<T> replace(PassRef<U>) WARN_UNUSED_RETURN;
private:
T* m_ptr;
};
template<typename T> template<typename U> inline PassRef<T> Ref<T>::replace(PassRef<U> reference)
{
auto oldReference = adoptRef(*m_ptr);
m_ptr = &reference.leakRef();
return oldReference;
}
} // namespace WTF
using WTF::Ref;
#endif // WTF_Ref_h
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