InternalClassUnions: Class unions in 'distr'
Description
Class unions in package distr defined for internal
purposes; these are OptionalNumeric,Objects from the Class
All of these classes are virtual:
No objects may be created from them.Details
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"numeric"or"NULL"; it is used e.g. for slotnuisanceof class"ParamFamParameter", as it may or may not be present but if so
it has to be numeric.