Since TTreeReaderArray<bool> does not deal correctly with std::vector<bool> (see
ROOT-9570), neither does RDataFrame when reading std::vector<bool> as RVec<bool>.
A workaround would be to read such columns with TTreeReaderValue<std::vector<bool>> but since users, by design, use RVec<bool> to indicate both a vector<bool> and a bool, this workaround breaks I/O of C-arrays of booleans.
Another option is to complain at runtime if we notice that an RVec<bool> is being used to read a std::vector<bool> column, suggesting to directly use a std::vector<bool> instead.
This issue is also a reminder that we must include tests for reading/writing of std::vector<bool> as well as fixed and variable sized arrays of booleans to be sure that all cases are dealt with appropriately.