Class WeakPointer

Modules/Core/include/mitkWeakPointer.h:43–294

   */
  template <class T>
  class WeakPointer final
  {
  public:
    /** \brief Callback type invoked when the observed object is deleted. */
    using DeleteEventCallbackType = std::function<void ()>;

    /** \brief Default constructor. Creates an expired weak pointer (null). */
    WeakPointer() noexcept
      : m_RawPointer(nullptr)
    {
    }

    /**
     * \brief Construct a weak pointer observing the given raw pointer.
     *
     * \param[in] rawPointer  The object to observe. May be nullptr.
     */
    WeakPointer(T *rawPointer)
      : m_RawPointer(rawPointer)
    {
      this->AddDeleteEventObserver();
    }

    /**
     * \brief Copy constructor. Observes the same object as \p other.
     *
     * \param[in] other  The weak pointer to copy from.
     */
    WeakPointer(const WeakPointer &other)
      : m_RawPointer(other.m_RawPointer)
    {
      this->AddDeleteEventObserver();
    }

    /**
     * \brief Move constructor. Takes over the observed object from \p other.
     *
     * After the move, \p other is in an expired state (null).
     *
     * \param[in] other  The weak pointer to move from.
     */
    WeakPointer(WeakPointer &&other)
      : m_RawPointer(other.m_RawPointer)
    {
      other.RemoveDeleteEventObserver();
      other.m_RawPointer = nullptr;
      this->AddDeleteEventObserver();
    }

    /** \brief Destructor. Removes the delete-event observer from the observed object. */
    ~WeakPointer() noexcept
    {
      try
      {
        this->RemoveDeleteEventObserver();
      }
      catch (...)
      {