The MetadataVisitorBase Class

Defined in: Keyview_Metadata.hpp

The MetadataVisitorBase class is an abstract base class that operates with the Metadatum::apply_visitor function. You use the MetadataVisitorBase class by defining a class that inherits from it, implementing the required pure virtual member functions to handle each of the possible metadata item value types. You then call apply_visitor with an instance of your new class. The apply_visitor function ensures that the correct member function of your visitor is called with the metadata item value in its original type.