- Your Widget Set For OpenGL

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usharedptr.hpp

/***************************************************************************
    LibUFO - UI For OpenGL
    copyright         : (C) 2001-2005 by Johannes Schmidt
    email             : schmidtjf at users.sourceforge.net
                             -------------------

    file              : include/ufo/usharedptr.hpp
    begin             : Thu Aug 22 2002
    $Id: usharedptr.hpp,v 1.9 2005/07/05 12:05:44 schmidtjf Exp $
 ***************************************************************************/

/***************************************************************************
 *  This library is free software; you can redistribute it and/or          *
 * modify it under the terms of the GNU Lesser General Public              *
 * License as published by the Free Software Foundation; either            *
 * version 2.1 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       *
 * Lesser General Public License for more details.                         *
 *                                                                         *
 * You should have received a copy of the GNU Lesser General Public        *
 * License along with this library; if not, write to the Free Software     *
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *
 ***************************************************************************/

#ifndef USHAREDPTR_HPP
#define USHAREDPTR_HPP

#include "config/ufo_config.hpp"

namespace ufo {

template<typename T>
class USharedPtr {
private:
    T * m_object; // shared object
    int * m_refCount; // shared counter

public:
    explicit USharedPtr() : m_object(NULL), m_refCount(NULL) {}

    explicit USharedPtr(const USharedPtr<T> & right) {
        if (right.m_object) {
            m_object = right.m_object;
            m_refCount = right.m_refCount;
            ++*m_refCount;
        } else {
            m_object = NULL;
            m_refCount = NULL;
        }
    }

    explicit USharedPtr(T * right) : m_object(NULL), m_refCount(NULL) {
        assign(right);
    }
    /*
    explicit USharedPtr(const T * right) : m_object(NULL), m_refCount(NULL) {
        assign(const_cast<T*>(right));
    }
    */
    ~USharedPtr() {
        release();
    }

    USharedPtr<T>& operator =(const USharedPtr<T>& right) {
        if (right.m_object) {
            ++*right.m_refCount;
        }

        release();

        m_object = right.m_object;
        m_refCount = right.m_refCount;

        return *this;
    }

    USharedPtr<T>& operator =(T* right) {
        assign(right);

        return *this;
    }
    /*
    USharedPtr<T>& operator =(const T* right) {
        assign(const_cast<T*>(right));

        return *this;
    }
    */
    bool valid() {
        return (m_object != NULL);
    }
    bool operator()() const {
        return (m_object != NULL);
    }
    bool operator!() const {
        return (m_object == NULL);
    }

    T * operator ->() const {
        return m_object;
    }

    T & operator *() const {
        return *m_object;
    }

    operator T*() const {
        return m_object;
    }
/* msvc6 don't like this for abstract classes
    operator T() const {
        return *m_object;
    }
*/
    int refCount() {
        return *m_refCount;
    }
private: // Private methods
    void assign(T * t) {
        if (t == m_object) { return; }

        release();
        if (t) {
            m_object = t;
            m_refCount = new int;
            *m_refCount = 1;
        }
    }
    void release() {
        if (m_object) {
            if (*m_refCount == 1) {
                delete m_refCount;
                delete m_object;
            } else {
                --*m_refCount;
            }
            m_object = NULL;
            m_refCount = NULL;
        }
    }
};

} // namespace ufo

#endif // USHAREDPTR_HPP

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