/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * Copyright 2008 by Sun Microsystems, Inc.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * $RCSfile: intruref.hxx,v $
 * $Revision: 1.5 $
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org 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 version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
 *
 ************************************************************************/

#ifndef SC_INTRUREF_HXX
#define SC_INTRUREF_HXX

/** A simple intrusive refcounting template, not thread safe, but therefore
    also a bit faster than boost's smart_ptr or uno::Reference equivalents, and
    the type to be refcounted has full control over its behavior.

    Mainly used in formula compiler and interpreter context, e.g. ScTokenRef,
    ScMatrixRef.

    Type T must implement methods IncRef() and DecRef(), in case typename T is
    const they must be const as well and the reference counter be mutable.
  */
template< typename T > class ScSimpleIntrusiveReference
{
    T* p;
public:
    inline ScSimpleIntrusiveReference() : p(0) {}
    inline ScSimpleIntrusiveReference( const ScSimpleIntrusiveReference& r )
    {
        p = r.p;
        if ( p )
            p->IncRef();
    }
    inline ScSimpleIntrusiveReference( T *t )
    {
        p = t;
        if ( p )
            t->IncRef();
    }
    inline void Clear()
    {
        if ( p )
        {
            p->DecRef();
            p = 0;
        }
    }
    inline ~ScSimpleIntrusiveReference()
    {
        if ( p )
            p->DecRef();
    }
    inline ScSimpleIntrusiveReference& operator=( T* t )
    {
        if ( t )
            t->IncRef();
        if ( p )
            p->DecRef();
        p = t;
        return *this;
    }
    inline ScSimpleIntrusiveReference& operator=( const ScSimpleIntrusiveReference& r )
    {
        *this = r.p;
        return *this;
    }
    inline bool Is() const              { return p != 0; }
    inline bool operator ! () const     { return p == 0; }
    inline T* operator&() const         { return p; }
    inline T* operator->() const        { return p; }
    inline T& operator*() const         { return *p; }
    inline operator T*() const          { return p; }
};

#endif // SC_INTRUREF_HXX