Add getConnection() method to IObject so we ask Object about its connection

include/sdbus-c++/IObject.h

@@ -173,6 +173,13 @@ namespace sdbus {
         */
         virtual void emitSignal(const sdbus::Signal& message) = 0;
 
+        /*!
+        * @brief Provides D-Bus connection used by the object
+        *
+        * @return Reference to the D-Bus connection
+        */
+        virtual sdbus::IConnection& getConnection() const = 0;
+
         /*!
         * @brief Registers method that the object will provide on D-Bus
         *

include/sdbus-c++/Interfaces.h

@@ -74,7 +74,7 @@ namespace sdbus {
      ***********************************************/
     template <typename... _Interfaces>
     class Interfaces
-        : private ObjectHolder<IObject>
+        : protected ObjectHolder<IObject>
         , public _Interfaces...
     {
     public:
@@ -96,7 +96,7 @@ namespace sdbus {
      ***********************************************/
     template <typename... _Interfaces>
     class ProxyInterfaces
-        : private ObjectHolder<IObjectProxy>
+        : protected ObjectHolder<IObjectProxy>
         , public _Interfaces...
     {
     public:

src/Object.cpp

@@ -130,6 +130,11 @@ void Object::emitSignal(const sdbus::Signal& message)
     message.send();
 }
 
+sdbus::IConnection& Object::getConnection() const
+{
+    return dynamic_cast<sdbus::IConnection&>(connection_);
+}
+
 const std::vector<sd_bus_vtable>& Object::createInterfaceVTable(InterfaceData& interfaceData)
 {
     auto& vtable = interfaceData.vtable_;

src/Object.h

@@ -77,6 +77,8 @@ namespace internal {
         sdbus::Signal createSignal(const std::string& interfaceName, const std::string& signalName) override;
         void emitSignal(const sdbus::Signal& message) override;
 
+        sdbus::IConnection& getConnection() const override;
+
     private:
         using InterfaceName = std::string;
         struct InterfaceData