The RDataSource implementation for the RNTupleProcessor.
It lets RDataFrame read combined (chained and joined) RNTuple data.
An RDataFrame that reads combined (chained and joined) RNTuple data, through the RNTupleProcessor. It can be constructed using FromRNTupleProcessor().
For each column containing an array or a collection, a corresponding column #colname is available to access colname.size() without reading and deserializing the collection values.
#include <ROOT/RNTupleProcessorDS.hxx>