/*
 *  smart_ptr.h
 *  elftosb
 *
 *  Created by Chris Reed on 4/18/06.
 *  Copyright 2006 __MyCompanyName__. All rights reserved.
 *
 */
#if !defined(_smart_ptr_h_)
#define _smart_ptr_h_

/*!
 * \brief Simple, standard smart pointer class.
 *
 * This class only supports the single-owner paradigm.
 */
template <typename T>
class smart_ptr
{
public:
    typedef T data_type;
    typedef T *ptr_type;
    typedef const T *const_ptr_type;
    typedef T &ref_type;
    typedef const T &const_ref_type;

    //! Default constuctor. Initialises with no pointer set.
    smart_ptr()
        : _p(0)
    {
    }

    //! This constructor takes a pointer to the object to be deleted.
    smart_ptr(ptr_type p)
        : _p(p)
    {
    }

    //! Destructor. If an object (pointer) has been set, it will be deleted.
    //! Deletes the object using safe_delete().
    virtual ~smart_ptr() { safe_delete(); }
    //! Return the current pointer value.
    ptr_type get() { return _p; }
    //! Return the const form of the current pointer value.
    const_ptr_type get() const { return _p; }
    //! Change the pointer value, or set if if the default constructor was used.
    //! If a pointer had previously been associated with the object, and \a p is
    //! different than that previous pointer, it will be deleted before taking
    //! ownership of \a p. If this is not desired, call reset() beforehand.
    void set(ptr_type p)
    {
        if (_p && p != _p)
        {
            safe_delete();
        }
        _p = p;
    }

    //! Dissociates any previously set pointer value without deleting it.
    void reset() { _p = 0; }
    //! Dissociates a previously set pointer value, deleting it at the same time.
    void clear() { safe_delete(); }
    //! Forces immediate deletion of the object. If you are planning on using
    //! this method, think about just using a normal pointer. It probably makes
    //! more sense.
    virtual void safe_delete()
    {
        if (_p)
        {
            delete _p;
            _p = 0;
        }
    }

    //! \name Operators
    //@{

    //! Makes the object transparent as the template type.
    operator ptr_type() { return _p; }
    //! Const version of the pointer operator.
    operator const_ptr_type() const { return _p; }
    //! Makes the object transparent as a reference of the template type.
    operator ref_type() { return *_p; }
    //! Const version of the reference operator.
    operator const_ref_type() const { return *_p; }
    //! Returns a boolean indicating whether the object has a pointer set or not.
    operator bool() const { return _p != 0; }
    //! To allow setting the pointer directly. Equivalent to a call to set().
    smart_ptr<T> &operator=(const_ptr_type p)
    {
        set(const_cast<ptr_type>(p));
        return *this;
    }

    //! Another operator to allow you to treat the object just like a pointer.
    ptr_type operator->() { return _p; }
    //! Another operator to allow you to treat the object just like a pointer.
    const_ptr_type operator->() const { return _p; }
    //	//! Pointer dereferencing operator.
    //	ref_type operator * () const { return *_p; }
    //
    //	//! Const version of the pointer dereference operator.
    //	const_ref_type operator * () const { return *_p; }

    //@}

protected:
    ptr_type _p; //!< The wrapped pointer.
};

/*!
 * \brief Simple, standard smart pointer class that uses the array delete operator.
 *
 * This class only supports the single-owner paradigm.
 *
 * This is almost entirely a copy of smart_ptr since the final C++ specification
 * does not allow template subclass members to access members  of the parent that
 * do not depend on the template parameter.
 */
template <typename T>
class smart_array_ptr
{
public:
    typedef T data_type;
    typedef T *ptr_type;
    typedef const T *const_ptr_type;
    typedef T &ref_type;
    typedef const T &const_ref_type;

    //! Default constuctor. Initialises with no pointer set.
    smart_array_ptr()
        : _p(0)
    {
    }

    //! This constructor takes a pointer to the object to be deleted.
    smart_array_ptr(ptr_type p)
        : _p(p)
    {
    }

    //! Destructor. If an array has been set, it will be deleted.
    //! Deletes the array using safe_delete().
    virtual ~smart_array_ptr() { safe_delete(); }
    //! Return the current pointer value.
    ptr_type get() { return _p; }
    //! Return the const form of the current pointer value.
    const_ptr_type get() const { return _p; }
    //! Change the pointer value, or set if if the default constructor was used.
    //! If a pointer had previously been associated with the object, and \a p is
    //! different than that previous pointer, it will be deleted before taking
    //! ownership of \a p. If this is not desired, call reset() beforehand.
    void set(ptr_type p)
    {
        if (_p && p != _p)
        {
            safe_delete();
        }
        _p = p;
    }

    //! Dissociates any previously set pointer value without deleting it.
    void reset() { _p = 0; }
    //! Dissociates a previously set pointer value, deleting it at the same time.
    void clear() { safe_delete(); }
    //! Forces immediate deletion of the object. If you are planning on using
    //! this method, think about just using a normal pointer. It probably makes
    //! more sense.
    virtual void safe_delete()
    {
        if (_p)
        {
            delete[] _p;
            _p = 0;
        }
    }

    //! \name Operators
    //@{

    //! Makes the object transparent as the template type.
    operator ptr_type() { return _p; }
    //! Const version of the pointer operator.
    operator const_ptr_type() const { return _p; }
    //! Makes the object transparent as a reference of the template type.
    operator ref_type() { return *_p; }
    //! Const version of the reference operator.
    operator const_ref_type() const { return *_p; }
    //! Returns a boolean indicating whether the object has a pointer set or not.
    operator bool() const { return _p != 0; }
    //! To allow setting the pointer directly. Equivalent to a call to set().
    smart_array_ptr<T> &operator=(const_ptr_type p)
    {
        set(const_cast<ptr_type>(p));
        return *this;
    }

    //! Another operator to allow you to treat the object just like a pointer.
    ptr_type operator->() { return _p; }
    //! Another operator to allow you to treat the object just like a pointer.
    const_ptr_type operator->() const { return _p; }
    //! Indexing operator.
    ref_type operator[](unsigned index) { return _p[index]; }
    //! Indexing operator.
    const_ref_type operator[](unsigned index) const { return _p[index]; }
    //	//! Pointer dereferencing operator.
    //	ref_type operator * () const { return *_p; }
    //
    //	//! Const version of the pointer dereference operator.
    //	const_ref_type operator * () const { return *_p; }

    //@}

protected:
    ptr_type _p; //!< The wrapped pointer.
};

#endif // _smart_ptr_h_