vtkWeakPointerBase.h

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/*=========================================================================
 
  Program:   Visualization Toolkit
  Module:    vtkWeakPointerBase.h
 
  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
 
     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.
 
=========================================================================*/
#ifndef vtkWeakPointerBase_h
#define vtkWeakPointerBase_h
 
#include "vtkCommonCoreModule.h" // For export macro
#include "vtkObjectBase.h"
 
class vtkObjectBaseToWeakPointerBaseFriendship;
 
class VTKCOMMONCORE_EXPORT vtkWeakPointerBase
{
public:
  vtkWeakPointerBase() noexcept
    : Object(nullptr)
  {
  }
 
  vtkWeakPointerBase(vtkObjectBase* r);
 
  vtkWeakPointerBase(const vtkWeakPointerBase& r);
 
  vtkWeakPointerBase(vtkWeakPointerBase&& r) noexcept;
 
  ~vtkWeakPointerBase();
 
 
  vtkWeakPointerBase& operator=(vtkObjectBase* r);
  vtkWeakPointerBase& operator=(const vtkWeakPointerBase& r);
  vtkWeakPointerBase& operator=(vtkWeakPointerBase&& r) noexcept;
 
  vtkObjectBase* GetPointer() const
  {
    // Inline implementation so smart pointer comparisons can be fully
    // inlined.
    return this->Object;
  }
 
private:
  friend class vtkObjectBaseToWeakPointerBaseFriendship;
 
protected:
  // Initialize weak pointer to given object.
  class NoReference
  {
  };
  vtkWeakPointerBase(vtkObjectBase* r, const NoReference&);
 
  // Pointer to the actual object.
  vtkObjectBase* Object;
};
 
//----------------------------------------------------------------------------
#define VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(op)                                                  \
  inline bool operator op(const vtkWeakPointerBase& l, const vtkWeakPointerBase& r)                \
  {                                                                                                \
    return (static_cast<void*>(l.GetPointer()) op static_cast<void*>(r.GetPointer()));             \
  }                                                                                                \
  inline bool operator op(vtkObjectBase* l, const vtkWeakPointerBase& r)                           \
  {                                                                                                \
    return (static_cast<void*>(l) op static_cast<void*>(r.GetPointer()));                          \
  }                                                                                                \
  inline bool operator op(const vtkWeakPointerBase& l, vtkObjectBase* r)                           \
  {                                                                                                \
    return (static_cast<void*>(l.GetPointer()) op static_cast<void*>(r));                          \
  }
VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(==)
VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(!=)
VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(<)
VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(<=)
VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(>)
VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR(>=)
 
#undef VTK_WEAK_POINTER_BASE_DEFINE_OPERATOR
 
VTKCOMMONCORE_EXPORT ostream& operator<<(ostream& os, const vtkWeakPointerBase& p);
 
#endif
// VTK-HeaderTest-Exclude: vtkWeakPointerBase.h