Q: fKeep thing in TClonesArray

Pasha Murat (murat@cdfsga.fnal.gov)
Sun, 5 Jul 1998 23:31:00 -0500 (CDT)


Hello ,

I'm curious about the role of fKeep data member in TClonesArray.
I recently realized that TClonesArray maintains 2 parallel arrays of
TObject*'s which it also tries to keep in sync - see
TClonesArray::operator[]. I'd expect that this procedure roughly doubles
the TObject* retrieval time and makes the bookkeping within the TClonesArray
kind of non-trivial.

I guess that from educational point of view it would be pretty interesting
(and not only for me) to know what are the advantages of keeping a duplicate
array of TObject*'s - it is definitely not something lying on the surface.

I'd appreciate any comments, thanks, Pasha.