// -*- mode: C++ -*- /* * ref_ptr. A reference counted template class. Similar to the STL * auto_ptr, but generalised for reference counting. * * Copyright (C) 2002 Barnaby Gray <barnaby@beedesign.co.uk> * * 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 REF_PTR_H #define REF_PTR_H namespace ICQ2000 { template <typename Object> class ref_ptr { protected: Object *m_instance; /* note: the actual reference count is controlled on the object - it turned out problematic having it stored in the ref_ptr, for reasons I won't go into here ;-) */ public: ref_ptr() : m_instance(NULL) { } ref_ptr(const ref_ptr<Object>& that) : m_instance(that.m_instance) { if (m_instance != NULL) ++(m_instance->count); } ref_ptr(Object *o) : m_instance(o) { if (m_instance != NULL) ++(m_instance->count); /* zeroed inside Contact now */ } ~ref_ptr() { if (m_instance != NULL && --(m_instance->count) == 0) delete m_instance; } Object* get() { return m_instance; } const Object* get() const { return m_instance; } Object* operator->() { return m_instance; } const Object* operator->() const { return m_instance; } Object& operator*() { return *m_instance; } const Object& operator*() const { return *m_instance; } // for debugging unsigned int count() const { return m_instance->count; } ref_ptr& operator=(const ref_ptr<Object>& that) { if (m_instance != NULL && --(m_instance->count) == 0) { delete m_instance; } m_instance = that.m_instance; if (m_instance != NULL) ++(m_instance->count); return *this; } }; } #endif