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/*========================================================================= |
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Program: Insight Segmentation & Registration Toolkit |
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Module: $RCSfile: itkSmartPointer.h.html,v $ |
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Language: C++ |
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Date: $Date: 2006/01/17 19:15:48 $ |
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Version: $Revision: 1.4 $ |
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Copyright (c) Insight Software Consortium. All rights reserved. |
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See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details. |
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This software is distributed WITHOUT ANY WARRANTY; without even |
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the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR |
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PURPOSE. See the above copyright notices for more information. |
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=========================================================================*/ |
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#ifndef __itkSmartPointer_h |
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#define __itkSmartPointer_h |
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#include "itkMacro.h" |
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#include <iostream> |
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namespace itk |
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{ |
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/** \class SmartPointer |
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* \brief Implements transparent reference counting. |
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* |
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* SmartPointer implements reference counting by overloading |
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* operator -> (and *) among others. This allows natural interface |
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* to the class referred to by the pointer without having to invoke |
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* special Register()/UnRegister() methods directly. |
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* |
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* To compile / test this class |
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* Windows: cl SmartPointerTest.cxx; .\SmartPointerTest.exe |
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* linux: c++ SmartPointerTest.cxx ./a.out |
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* other: CCcompiler SmartPointerTest.cxx ./a.out |
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* |
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* \ingroup ITKSystemObjects |
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* \ingroup DataAccess |
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*/ |
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template <class TObjectType> |
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class ITK_EXPORT SmartPointer |
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{ |
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public: |
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typedef TObjectType ObjectType; |
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/** Constructor */ |
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SmartPointer () |
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{ m_Pointer = 0; } |
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/** Copy constructor */ |
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SmartPointer (const SmartPointer<ObjectType> &p): |
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****m_Pointer(p.m_Pointer) |
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{ this->Register(); } |
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/** Constructor to pointer p */ |
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SmartPointer (ObjectType *p): |
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****m_Pointer(p) |
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{ this->Register(); } |
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/** Destructor */ |
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~SmartPointer () |
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{ |
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this->UnRegister(); |
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m_Pointer = 0; |
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} |
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/** Overload operator -> */ |
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ObjectType *operator -> () const |
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{ return m_Pointer; } |
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/** Return pointer to object. */ |
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operator ObjectType * () const |
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{ return m_Pointer; } |
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/** Test if the pointer has been initialized */ |
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bool IsNotNull() const |
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**{ return m_Pointer != 0; } |
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bool IsNull() const |
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**{ return m_Pointer == 0; } |
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/** Template comparison operators. */ |
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template <typename R> |
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bool operator == ( R r ) const |
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{ return (m_Pointer == static_cast<const ObjectType*>(r) ); } |
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template <typename R> |
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bool operator != ( R r ) const |
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{ return (m_Pointer != static_cast<const ObjectType*>(r) ); } |
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/** Access function to pointer. */ |
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ObjectType *GetPointer () const |
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{ return m_Pointer; } |
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/** Comparison of pointers. Less than comparison. */ |
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bool operator < (const SmartPointer &r) const |
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{ return (void*)m_Pointer < (void*) r.m_Pointer; } |
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/** Comparison of pointers. Greater than comparison. */ |
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bool operator > (const SmartPointer &r) const |
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{ return (void*)m_Pointer > (void*) r.m_Pointer; } |
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/** Comparison of pointers. Less than or equal to comparison. */ |
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bool operator <= (const SmartPointer &r) const |
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{ return (void*)m_Pointer <= (void*) r.m_Pointer; } |
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/** Comparison of pointers. Greater than or equal to comparison. */ |
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bool operator >= (const SmartPointer &r) const |
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{ return (void*)m_Pointer >= (void*) r.m_Pointer; } |
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/** Overload operator assignment. */ |
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SmartPointer &operator = (const SmartPointer &r) |
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{ return this->operator = (r.GetPointer()); } |
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/** Overload operator assignment. */ |
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SmartPointer &operator = (ObjectType *r) |
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{ |
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if (m_Pointer != r) |
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{ |
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ObjectType* tmp = m_Pointer; //avoid recursive unregisters by retaining temporarily |
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m_Pointer = r; |
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this->Register(); |
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if ( tmp ) { tmp->UnRegister(); } |
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} |
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return *this; |
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} |
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/** Function to print object pointed to */ |
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ObjectType *Print (std::ostream& os) const |
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{ |
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******// This prints the object pointed to by the pointer |
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******(*m_Pointer).Print(os); |
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******return m_Pointer; |
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} |
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private: |
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/** The pointer to the object referrred to by this smart pointer. */ |
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ObjectType* m_Pointer; |
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void Register() |
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{ |
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if(m_Pointer) { m_Pointer->Register(); } |
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} |
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void UnRegister() |
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{ |
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if(m_Pointer) { m_Pointer->UnRegister(); } |
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} |
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}; |
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template <typename T> |
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std::ostream& operator<< (std::ostream& os, SmartPointer<T> p) |
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{ |
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p.Print(os); |
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return os; |
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} |
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} // end namespace itk |
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#endif |
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