to_root_raw.cpp

void to_root_raw()
{
	// Create a reader from CSV
	csv::CSVReader reader("checkouts-by-title.csv");

	// Create a ROOT File. For the first pass, we'll be saving everything as a string
	auto f = new TFile("library.root", "recreate");
	TTree *t = new TTree("library_raw","raw data from csv file");
	auto fields = reader.get_col_names();
	auto buf = std::vector<std::string>(fields.size());

	// Assign each buffer to a buffer
	for(size_t i=0;i<fields.size();i++)
		t->Branch(fields[i].c_str(), &buf[i]);

	// Copy data from CSV to ROOT
	for (auto& row: reader) { 
		for(size_t i=0;i<fields.size();i++)
			buf[i] = row[fields[i]].get();
		t->Fill();
	}

	// Write the data to root
	f->Write();
}