spl/LazyLoadPtr.h

/*
 *   This file is part of the Standard Portable Library (SPL).
 *
 *   SPL is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   SPL 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with SPL.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef _createonaccessptr_h
#define _createonaccessptr_h

#include <spl/Memory.h>

template <class T> class LazyLoadPtr : public IMemoryValidate
{
private:
        T* m_ptr;

        void Create()
        {
                if (NULL == m_ptr) 
                {
                        m_ptr = new T();
                }
        }

        LazyLoadPtr(const LazyLoadPtr&) 
        {
        }

        LazyLoadPtr& operator =(const LazyLoadPtr&) 
        {
        }

public:
        LazyLoadPtr()
        : m_ptr(NULL) 
        {
        }

        ~LazyLoadPtr()
        {
                if (NULL != m_ptr)
                {
                        delete m_ptr;
                }
        }

        T& operator*()
        {
                Create(); 
                return *m_ptr;
        }

        T* operator->()
        {
                Create(); 
                return m_ptr;
        }

        T* Get()
        {
                Create(); 
                return m_ptr;
        }
        
#ifdef DEBUG
        virtual void ValidateMem() const
        {
                if (NULL != m_ptr)
                {
                        ValidateType(m_ptr);
                }
        }

        virtual void CheckMem() const
        {
                if (NULL != m_ptr)
                {
                        ValidateType(m_ptr);
                }
        }
#endif
};

#endif