Data storage for user-defined measurements

A Variant value.  

[out, retval]

object.UserData [= value]

The UserData Property syntax has these parts:

The McUserMeasure object that implements a user-defined measurement is shared by potentially many instances of the McMeasure object from which the measurement Value is obtained. The reason for this is that McEngine.RegisterUserMeasurement is passed a single instance of a McUserMeasure object which then serves as the “compute engine” on all parent McFeatures where the measurement is accessed. Thus there needs to be some place that an McUserMeasure object can store data on a per-McMeasure basis. This property serves that purpose. The McUserMeasure object is passed the calling McMeasure object when its UserAttributes, ComputeValue or UserIsValueStale methods are called; it can use this object to store and retrieve per-measurement instance values or properties.