137 lines
4.5 KiB
C++
137 lines
4.5 KiB
C++
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
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*
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* This library is open source and may be redistributed and/or modified under
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* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
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* (at your option) any later version. The full license is in LICENSE file
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* included with this distribution, and on the openscenegraph.org website.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* OpenSceneGraph Public License for more details.
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*/
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#ifndef OSG_REF_PTR
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#define OSG_REF_PTR 1
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#include <osg/Config>
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namespace osg {
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/** Smart pointer for handling referenced counted objects.*/
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template<class T>
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class ref_ptr
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{
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public:
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typedef T element_type;
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ref_ptr() : _ptr(0) {}
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ref_ptr(T* ptr) : _ptr(ptr) { if (_ptr) _ptr->ref(); }
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ref_ptr(const ref_ptr& rp) : _ptr(rp._ptr) { if (_ptr) _ptr->ref(); }
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template<class Other> ref_ptr(const ref_ptr<Other>& rp) : _ptr(rp._ptr) { if (_ptr) _ptr->ref(); }
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~ref_ptr() { if (_ptr) _ptr->unref(); _ptr = 0; }
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ref_ptr& operator = (const ref_ptr& rp)
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{
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assign(rp);
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return *this;
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}
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template<class Other> ref_ptr& operator = (const ref_ptr<Other>& rp)
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{
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assign(rp);
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return *this;
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}
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inline ref_ptr& operator = (T* ptr)
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{
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if (_ptr==ptr) return *this;
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T* tmp_ptr = _ptr;
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_ptr = ptr;
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if (_ptr) _ptr->ref();
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// unref second to prevent any deletion of any object which might
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// be referenced by the other object. i.e rp is child of the
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// original _ptr.
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if (tmp_ptr) tmp_ptr->unref();
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return *this;
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}
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#ifdef OSG_USE_REF_PTR_IMPLICIT_OUTPUT_CONVERSION
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// implicit output conversion
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operator T*() const { return _ptr; }
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#else
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// comparison operators for ref_ptr.
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bool operator == (const ref_ptr& rp) const { return (_ptr==rp._ptr); }
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bool operator == (const T* ptr) const { return (_ptr==ptr); }
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friend bool operator == (const T* ptr, const ref_ptr& rp) { return (ptr==rp._ptr); }
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bool operator != (const ref_ptr& rp) const { return (_ptr!=rp._ptr); }
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bool operator != (const T* ptr) const { return (_ptr!=ptr); }
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friend bool operator != (const T* ptr, const ref_ptr& rp) { return (ptr!=rp._ptr); }
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bool operator < (const ref_ptr& rp) const { return (_ptr<rp._ptr); }
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// follows is an implmentation of the "safe bool idiom", details can be found at:
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// http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Safe_bool
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// http://lists.boost.org/Archives/boost/2003/09/52856.php
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private:
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typedef T* ref_ptr::*unspecified_bool_type;
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public:
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// safe bool conversion
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operator unspecified_bool_type() const { return valid()? &ref_ptr::_ptr : 0; }
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#endif
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T& operator*() const { return *_ptr; }
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T* operator->() const { return _ptr; }
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T* get() const { return _ptr; }
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bool operator!() const { return _ptr==0; } // not required
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bool valid() const { return _ptr!=0; }
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T* release() { T* tmp=_ptr; if (_ptr) _ptr->unref_nodelete(); _ptr=0; return tmp; }
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void swap(ref_ptr& rp) { T* tmp=_ptr; _ptr=rp._ptr; rp._ptr=tmp; }
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private:
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template<class Other> void assign(const ref_ptr<Other>& rp)
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{
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if (_ptr==rp._ptr) return;
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T* tmp_ptr = _ptr;
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_ptr = rp._ptr;
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if (_ptr) _ptr->ref();
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// unref second to prevent any deletion of any object which might
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// be referenced by the other object. i.e rp is child of the
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// original _ptr.
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if (tmp_ptr) tmp_ptr->unref();
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}
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template<class Other> friend class ref_ptr;
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T* _ptr;
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};
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template<class T> inline
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void swap(ref_ptr<T>& rp1, ref_ptr<T>& rp2) { rp1.swap(rp2); }
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template<class T> inline
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T* get_pointer(const ref_ptr<T>& rp) { return rp.get(); }
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template<class T, class Y> inline
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ref_ptr<T> static_pointer_cast(const ref_ptr<Y>& rp) { return static_cast<T*>(rp.get()); }
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template<class T, class Y> inline
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ref_ptr<T> dynamic_pointer_cast(const ref_ptr<Y>& rp) { return dynamic_cast<T*>(rp.get()); }
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template<class T, class Y> inline
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ref_ptr<T> const_pointer_cast(const ref_ptr<Y>& rp) { return const_cast<T*>(rp.get()); }
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}
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#endif
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