Class unions in 'distr'
Class unions in package
These classes are used internally to make available methods or to allow slots of classes to be filled with varying types. In particular
"OptionalNumeric": may contain objects of class
"NULL"; it is used e.g. for slot
"ParamFamParameter", as it may or may not be present but if so it has to be numeric.
Objects from the Class
All of these classes are virtual: No objects may be created from them.