// -*- mode: c++; c-basic-offset: 4 -*-

/*

 *  Copyright (C) 2006, 2007 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_OwnPtr_h

#define WTF_OwnPtr_h

#include <algorithm>

#include <wtf/Assertions.h>

#include <wtf/Noncopyable.h>

#if PLATFORM(WIN)

typedef struct HBITMAP__* HBITMAP;

typedef struct HBRUSH__* HBRUSH;

typedef struct HFONT__* HFONT;

typedef struct HPALETTE__* HPALETTE;

typedef struct HPEN__* HPEN;

typedef struct HRGN__* HRGN;

#endif

namespace WTF {

    // Unlike most of our smart pointers, OwnPtr can take either the pointer type or the pointed-to type.

    // FIXME: Share a single RemovePointer class template with RetainPtr.

    template <typename T> struct OwnPtrRemovePointer { typedef T type; };

    template <typename T> struct OwnPtrRemovePointer<T*> { typedef T type; };

    template <typename T> inline void deleteOwnedPtr(T* ptr)

    {

        typedef char known[sizeof(T) ? 1 : -1];

        if (sizeof(known))

            delete ptr;

    }

#if PLATFORM(WIN)

    void deleteOwnedPtr(HBITMAP);

    void deleteOwnedPtr(HBRUSH);

    void deleteOwnedPtr(HFONT);

    void deleteOwnedPtr(HPALETTE);

    void deleteOwnedPtr(HPEN);

    void deleteOwnedPtr(HRGN);

#endif

    template <typename T> class OwnPtr : Noncopyable {

    public:

        typedef typename OwnPtrRemovePointer<T>::type ValueType;

        typedef ValueType* PtrType;

        explicit OwnPtr(PtrType ptr = 0) : m_ptr(ptr) { }

        ~OwnPtr() { deleteOwnedPtr(m_ptr); }

        PtrType get() const { return m_ptr; }

        PtrType release() { PtrType ptr = m_ptr; m_ptr = 0; return ptr; }

        void set(PtrType ptr) { ASSERT(!ptr || m_ptr != ptr); deleteOwnedPtr(m_ptr); m_ptr = ptr; }

        void clear() { deleteOwnedPtr(m_ptr); m_ptr = 0; }

        ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; }

        PtrType operator->() const { ASSERT(m_ptr); 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 (OwnPtr::*UnspecifiedBoolType)() const;

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

        void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); }

    private:

        PtrType m_ptr;

    };

    template <typename T> inline void swap(OwnPtr<T>& a, OwnPtr<T>& b) { a.swap(b); }

    template <typename T> inline typename OwnPtr<T>::PtrType getPtr(const OwnPtr<T>& p)

    {

        return p.get();

    }

} // namespace WTF

using WTF::OwnPtr;

#endif // WTF_OwnPtr_h