Add protected non-virtual destructor in generated classes

docs/using-sdbus-c++.md

@@ -525,7 +525,7 @@ After running this through the stubs generator, we get the stub code that is des
 
 ### concatenator-server-glue.h
 
-For each interface in the XML IDL file the generator creates one class that represents it. The class is de facto an interface which shall be implemented by inheriting from it. The class' constructor takes care of registering all methods, signals and properties. For each D-Bus method there is a pure virtual member function. These pure virtual functions must be implemented in the child class. For each signal, there is a public function member that emits this signal.
+For each interface in the XML IDL file the generator creates one class that represents it. The class is de facto an interface which shall be implemented by the class inheriting it. The class' constructor takes care of registering all methods, signals and properties. For each D-Bus method there is a pure virtual member function. These pure virtual functions must be implemented in the child class. For each signal, there is a public function member that emits this signal.
 
 ```cpp
 /*
@@ -555,6 +555,8 @@ protected:
         object_.registerSignal("concatenated").onInterface(INTERFACE_NAME).withParameters<std::string>();
     }
 
+    ~Concatenator_adaptor() = default;
+
 public:
     void emitConcatenated(const std::string& concatenatedString)
     {
@@ -604,6 +606,8 @@ protected:
         proxy_.uponSignal("concatenated").onInterface(INTERFACE_NAME).call([this](const std::string& concatenatedString){ this->onConcatenated(concatenatedString); });
     }
 
+    ~Concatenator_proxy() = default;
+
     virtual void onConcatenated(const std::string& concatenatedString) = 0;
 
 public:
@@ -1062,12 +1066,14 @@ public:
         object_.registerProperty("status").onInterface(INTERFACE_NAME).withGetter([this](){ return this->status(); }).withSetter([this](const uint32_t& value){ this->status(value); });
     }
 
+    ~PropertyProvider_adaptor() = default;
+
 private:
     // property getter
     virtual uint32_t status() = 0;
     // property setter
     virtual void status(const uint32_t& value) = 0;
-    
+
     /*...*/
 };
 #endif
@@ -1079,7 +1085,7 @@ The proxy:
 class PropertyProvider_proxy
 {
     /*...*/
-    
+
 public:
     // getting the property value
     uint32_t status()
@@ -1092,7 +1098,7 @@ public:
     {
         object_.setProperty("status").onInterface(INTERFACE_NAME).toValue(value);
     }
-    
+
     /*...*/
 };
 ```

include/sdbus-c++/StandardInterfaces.h

@@ -46,6 +46,8 @@ namespace sdbus {
         {
         }
 
+        ~Peer_proxy() = default;
+
     public:
         void Ping()
         {
@@ -74,6 +76,8 @@ namespace sdbus {
         {
         }
 
+        ~Introspectable_proxy() = default;
+
     public:
         std::string Introspect()
         {
@@ -106,6 +110,8 @@ namespace sdbus {
                             });
         }
 
+        ~Properties_proxy() = default;
+
         virtual void onPropertiesChanged( const std::string& interfaceName
                                         , const std::map<std::string, sdbus::Variant>& changedProperties
                                         , const std::vector<std::string>& invalidatedProperties ) = 0;
@@ -160,6 +166,8 @@ namespace sdbus {
                             });
         }
 
+        ~ObjectManager_proxy() = default;
+
         virtual void onInterfacesAdded( const sdbus::ObjectPath& objectPath
                                       , const std::map<std::string, std::map<std::string, sdbus::Variant>>& interfacesAndProperties) = 0;
         virtual void onInterfacesRemoved( const sdbus::ObjectPath& objectPath
@@ -192,6 +200,8 @@ namespace sdbus {
         {
         }
 
+        ~Properties_adaptor() = default;
+
     public:
         void emitPropertiesChangedSignal(const std::string& interfaceName, const std::vector<std::string>& properties)
         {
@@ -219,6 +229,8 @@ namespace sdbus {
             object_.addObjectManager();
         }
 
+        ~ObjectManager_adaptor() = default;
+
     public:
         void emitInterfacesAddedSignal()
         {

tests/integrationtests/adaptor-glue.h

@@ -52,7 +52,6 @@ using ComplexType = std::map<
 
 class testing_adaptor
 {
-
 protected:
     testing_adaptor(sdbus::IObject& object) :
         object_(object)
@@ -115,9 +114,10 @@ protected:
         object_.registerProperty("action").onInterface(INTERFACE_NAME).withGetter([this](){ return this->action(); }).withSetter([this](const uint32_t& value){ this->action(value); }).withUpdateBehavior(sdbus::Flags::EMITS_INVALIDATION_SIGNAL);
         //object_.registerProperty("blocking").onInterface(INTERFACE_NAME)./*withGetter([this](){ return this->blocking(); }).*/withSetter([this](const bool& value){ this->blocking(value); });
         object_.registerProperty("blocking").onInterface(INTERFACE_NAME).withGetter([this](){ return this->blocking(); }).withSetter([this](const bool& value){ this->blocking(value); });
-
     }
 
+    ~testing_adaptor() = default;
+
 public:
     void emitSimpleSignal()
     {

tests/integrationtests/proxy-glue.h

@@ -45,6 +45,8 @@ protected:
                 { this->onSignalWithoutRegistration(s); });
     }
 
+    ~testing_proxy() = default;
+
     virtual void onSimpleSignal() = 0;
     virtual void onSignalWithMap(const std::map<int32_t, std::string>& map) = 0;
     virtual void onSignalWithVariant(const sdbus::Variant& v) = 0;

tests/perftests/perftests-adaptor.h

@@ -27,6 +27,8 @@ protected:
         object_.registerSignal("dataSignal").onInterface(INTERFACE_NAME).withParameters<std::string>();
     }
 
+    ~perftests_adaptor() = default;
+
 public:
     void emitDataSignal(const std::string& data)
     {

tests/perftests/perftests-proxy.h

@@ -25,6 +25,8 @@ protected:
         proxy_.uponSignal("dataSignal").onInterface(INTERFACE_NAME).call([this](const std::string& data){ this->onDataSignal(data); });
     }
 
+    ~perftests_proxy() = default;
+
     virtual void onDataSignal(const std::string& data) = 0;
 
 public:

tests/stresstests/celsius-thermometer-adaptor.h

@@ -27,6 +27,8 @@ protected:
         object_.registerMethod("getCurrentTemperature").onInterface(INTERFACE_NAME).implementedAs([this](){ return this->getCurrentTemperature(); });
     }
 
+    ~thermometer_adaptor() = default;
+
 private:
     virtual uint32_t getCurrentTemperature() = 0;
 

tests/stresstests/celsius-thermometer-proxy.h

@@ -26,6 +26,8 @@ protected:
     {
     }
 
+    ~thermometer_proxy() = default;
+
 public:
     uint32_t getCurrentTemperature()
     {

tests/stresstests/concatenator-adaptor.h

@@ -27,6 +27,8 @@ protected:
         object_.registerSignal("concatenatedSignal").onInterface(INTERFACE_NAME).withParameters<std::string>();
     }
 
+    ~concatenator_adaptor() = default;
+
 public:
     void emitConcatenatedSignal(const std::string& concatenatedString)
     {

tests/stresstests/concatenator-proxy.h

@@ -26,6 +26,8 @@ protected:
         proxy_.uponSignal("concatenatedSignal").onInterface(INTERFACE_NAME).call([this](const std::string& concatenatedString){ this->onConcatenatedSignal(concatenatedString); });
     }
 
+    ~concatenator_proxy() = default;
+
     virtual void onConcatenatedSignal(const std::string& concatenatedString) = 0;
 
     virtual void onConcatenateReply(const std::string& result, const sdbus::Error* error) = 0;

tests/stresstests/fahrenheit-thermometer-adaptor.h

@@ -27,6 +27,8 @@ protected:
         object_.registerMethod("getCurrentTemperature").onInterface(INTERFACE_NAME).implementedAs([this](){ return this->getCurrentTemperature(); });
     }
 
+    ~thermometer_adaptor() = default;
+
 private:
     virtual uint32_t getCurrentTemperature() = 0;
 
@@ -55,6 +57,8 @@ protected:
         object_.registerMethod("destroyDelegateObject").onInterface(INTERFACE_NAME).implementedAs([this](sdbus::Result<>&& result, sdbus::ObjectPath delegate){ this->destroyDelegateObject(std::move(result), std::move(delegate)); }).withNoReply();
     }
 
+    ~factory_adaptor() = default;
+
 private:
     virtual void createDelegateObject(sdbus::Result<sdbus::ObjectPath>&& result) = 0;
     virtual void destroyDelegateObject(sdbus::Result<>&& result, sdbus::ObjectPath delegate) = 0;

tests/stresstests/fahrenheit-thermometer-proxy.h

@@ -26,6 +26,8 @@ protected:
     {
     }
 
+    ~thermometer_proxy() = default;
+
 public:
     uint32_t getCurrentTemperature()
     {
@@ -57,6 +59,8 @@ protected:
     {
     }
 
+    ~factory_proxy() = default;
+
 public:
     sdbus::ObjectPath createDelegateObject()
     {

tools/xml2cpp-codegen/AdaptorGenerator.cpp

@@ -130,6 +130,8 @@ std::string AdaptorGenerator::processInterface(Node& interface) const
                        << propertyRegistration
          << tab << "}" << endl << endl;
 
+    body << tab << "~" << className << "() = default;" << endl << endl;
+
     if (!signalMethods.empty())
     {
         body << "public:" << endl << signalMethods;

tools/xml2cpp-codegen/ProxyGenerator.cpp

@@ -95,6 +95,9 @@ std::string ProxyGenerator::processInterface(Node& interface) const
     body << tab << "{" << endl
             << registration
             << tab << "}" << endl << endl;
+
+    body << tab << "~" << className << "() = default;" << endl << endl;
+
     if (!declaration.empty())
         body << declaration << endl;