Resolve "Factory for state blocks"

Closes #321 (closed)

include/core/common/factory.h

@@ -244,7 +244,7 @@ class Factory
         bool registerCreator(const std::string& _type, CreatorCallback createFn);
         bool unregisterCreator(const std::string& _type);
         TypeBasePtr create(const std::string& _type, TypeInput... _input);
-        std::string getClass();
+        std::string getClass() const;
 
     private:
         CallbackMap callbacks_;
@@ -301,7 +301,7 @@ inline Factory<TypeBase, TypeInput...>& Factory<TypeBase, TypeInput...>::get()
 }
 
 template<class TypeBase, typename... TypeInput>
-inline std::string Factory<TypeBase, TypeInput...>::getClass()
+inline std::string Factory<TypeBase, TypeInput...>::getClass() const
 {
     return "Factory<class TypeBase>";
 }
@@ -319,7 +319,7 @@ class LandmarkBase;
 typedef Factory<LandmarkBase,
         const YAML::Node&>  FactoryLandmark;
 template<>
-inline std::string FactoryLandmark::getClass()
+inline std::string FactoryLandmark::getClass() const
 {
     return "FactoryLandmark";
 }