/*

 * Copyright (C) 2010 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 WKRetainPtr_h

#define WKRetainPtr_h

#include <algorithm>

namespace WebKit {

enum WKAdoptTag { AdoptWK };

template <typename T>

class WKRetainPtr {

public:

    typedef T PtrType;

    WKRetainPtr()

        : m_ptr(0)

    {

    }

    WKRetainPtr(PtrType ptr)

        : m_ptr(ptr)

    {

        if (ptr)

            WKRetain(ptr);

    }

    WKRetainPtr(WKAdoptTag, PtrType ptr)

        : m_ptr(ptr)

    {

    }

    template <typename U>

    WKRetainPtr(const WKRetainPtr<U>& o)

        : m_ptr(o.get())

    {

        if (PtrType ptr = m_ptr)

            WKRetain(ptr);

    }

    WKRetainPtr(const WKRetainPtr& o)

        : m_ptr(o.m_ptr)

    {

        if (PtrType ptr = m_ptr)

            WKRetain(ptr);

    }

    ~WKRetainPtr()

    {

        if (PtrType ptr = m_ptr)

            WKRelease(ptr);

    }

    PtrType get() const { return m_ptr; }

    PtrType releaseRef() { PtrType tmp = m_ptr; m_ptr = 0; return tmp; }

    PtrType 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 PtrType WKRetainPtr::*UnspecifiedBoolType;

    operator UnspecifiedBoolType() const { return m_ptr ? &WKRetainPtr::m_ptr : 0; }

    WKRetainPtr& operator=(const WKRetainPtr&);

    template <typename U> WKRetainPtr& operator=(const WKRetainPtr<U>&);

    WKRetainPtr& operator=(PtrType);

    template <typename U> WKRetainPtr& operator=(U*);

    void adopt(PtrType);

    void swap(WKRetainPtr&);

private:

    PtrType m_ptr;

};

template <typename T> inline WKRetainPtr<T>& WKRetainPtr<T>::operator=(const WKRetainPtr<T>& o)

{

    PtrType optr = o.get();

    if (optr)

        WKRetain(optr);

    PtrType ptr = m_ptr;

    m_ptr = optr;

    if (ptr)

        WKRelease(ptr);

    return *this;

}

template <typename T> template <typename U> inline WKRetainPtr<T>& WKRetainPtr<T>::operator=(const WKRetainPtr<U>& o)

{

    PtrType optr = o.get();

    if (optr)

        WKRetain(optr);

    PtrType ptr = m_ptr;

    m_ptr = optr;

    if (ptr)

        WKRelease(ptr);

    return *this;

}

template <typename T> inline WKRetainPtr<T>& WKRetainPtr<T>::operator=(PtrType optr)

{

    if (optr)

        WKRetain(optr);

    PtrType ptr = m_ptr;

    m_ptr = optr;

    if (ptr)

        WKRelease(ptr);

    return *this;

}

template <typename T> inline void WKRetainPtr<T>::adopt(PtrType optr)

{

    PtrType ptr = m_ptr;

    m_ptr = optr;

    if (ptr)

        WKRelease(ptr);

}

template <typename T> template <typename U> inline WKRetainPtr<T>& WKRetainPtr<T>::operator=(U* optr)

{

    if (optr)

        WKRetain(optr);

    PtrType ptr = m_ptr;

    m_ptr = optr;

    if (ptr)

        WKRelease(ptr);

    return *this;

}

template <class T> inline void WKRetainPtr<T>::swap(WKRetainPtr<T>& o)

{

    std::swap(m_ptr, o.m_ptr);

}

template <class T> inline void swap(WKRetainPtr<T>& a, WKRetainPtr<T>& b)

{

    a.swap(b);

}

template <typename T, typename U> inline bool operator==(const WKRetainPtr<T>& a, const WKRetainPtr<U>& b)

{ 

    return a.get() == b.get(); 

}

template <typename T, typename U> inline bool operator==(const WKRetainPtr<T>& a, U* b)

{ 

    return a.get() == b; 

}

template <typename T, typename U> inline bool operator==(T* a, const WKRetainPtr<U>& b) 

{

    return a == b.get(); 

}

template <typename T, typename U> inline bool operator!=(const WKRetainPtr<T>& a, const WKRetainPtr<U>& b)

{ 

    return a.get() != b.get(); 

}

template <typename T, typename U> inline bool operator!=(const WKRetainPtr<T>& a, U* b)

{

    return a.get() != b; 

}

template <typename T, typename U> inline bool operator!=(T* a, const WKRetainPtr<U>& b)

{ 

    return a != b.get(); 

}

} // namespace WebKit

using WebKit::WKRetainPtr;

using WebKit::AdoptWK;

#endif // WKRetainPtr_h