Inherited by MyUserInfo.
a base class to hold extra user information in a PseudoJet
This is a base class to help associate extra user information with a jet. The user should store their information in a class derived from this. This allows information of arbitrary complexity to be easily associated with a PseudoJet (in contrast to the user index). For example, in a Monte Carlo simulation, the user information might include the PDG ID, and the position of the production vertex for the particle.
The PseudoJet is able to store a shared pointer to any object derived from UserInfo. The use of a shared pointer frees the user of the need to handle the memory management associated with the information.
Having the user information derive from a common base class also facilitates dynamic casting, etc.