Merged requested to merge jchapman/athena:AthSimulationHepMC3Prep_master into master
This merge request mainly makes the following replacements for classes which are part of the AthSimulation project:
HepMC::GenParticle* --> HepMC::GenParticlePtr const HepMC::GenParticle* --> HepMC::ConstGenParticlePtr HepMC::GenVertex* --> HepMC::GenVertexPtr const HepMC::GenVertex* --> HepMC::ConstGenVertexPtr
Plus a few other syntax replacements to use helper functions defined in
The purpose is to prepare for the migration from HepMC2 to HepMC3. Further syntax changes will be required.