cout << "total constructions/destructions --> " << total_constructions_ << "/" << total_destructions_ << endl;
printf("total constructions/destructions --> %d/%d\n", total_constructions_, total_destructions_);
IFoo::print_totals()  {    cout << "total constructions/destructions --> " << total_constructions_ << "/" << total_destructions_ << endl;  }