App: implement '*' operator for weak pointer classes

src/App/DocumentObserver.cpp

@@ -593,7 +593,12 @@ bool DocumentWeakPtrT::expired() const noexcept
     return (d->_document == nullptr);
 }
 
-App::Document* DocumentWeakPtrT::operator->() noexcept
+App::Document* DocumentWeakPtrT::operator*() const noexcept
+{
+    return d->_document;
+}
+
+App::Document* DocumentWeakPtrT::operator->() const noexcept
 {
     return d->_document;
 }
@@ -686,7 +691,12 @@ DocumentObjectWeakPtrT& DocumentObjectWeakPtrT::operator= (App::DocumentObject*
     return *this;
 }
 
-App::DocumentObject* DocumentObjectWeakPtrT::operator->() noexcept
+App::DocumentObject* DocumentObjectWeakPtrT::operator*() const noexcept
+{
+    return d->get();
+}
+
+App::DocumentObject* DocumentObjectWeakPtrT::operator->() const noexcept
 {
     return d->get();
 }

src/App/DocumentObserver.h

@@ -294,11 +294,16 @@ public:
      * \return true if the managed object has already been deleted, false otherwise.
      */
     bool expired() const noexcept;
+    /*!
+     * \brief operator *
+     * \return pointer to the document
+     */
+    App::Document* operator*() const noexcept;
     /*!
      * \brief operator ->
      * \return pointer to the document
      */
-    App::Document* operator->() noexcept;
+    App::Document* operator->() const noexcept;
 
 private:
     // disable
@@ -334,10 +339,15 @@ public:
      */
     DocumentObjectWeakPtrT& operator= (App::DocumentObject* p);
     /*!
-     * \brief operator ->
-     * \return pointer to the document
+     * \brief operator *
+     * \return pointer to the document object
      */
-    App::DocumentObject* operator->() noexcept;
+    App::DocumentObject* operator*() const noexcept;
+    /*!
+     * \brief operator ->
+     * \return pointer to the document object
+     */
+    App::DocumentObject* operator->() const noexcept;
     /*!
      * \brief operator ==
      * \return true if both objects are equal, false otherwise
@@ -400,6 +410,13 @@ public:
         ptr = p;
         return *this;
     }
+    /*!
+     * \brief operator ->
+     * \return pointer to the document object
+     */
+    T* operator*() const {
+        return ptr.get<T>();
+    }
     /*!
      * \brief operator ->
      * \return pointer to the document object