{
int v_i = 0;
TFile *hfile = hfile = TFile::Open("o.root","RECREATE", "", 207);
TTree *tree = new TTree("T","data for rust tests");
tree->Branch("v_i",&v_i);
for (int i = -10; i < 10; ++i)
{
v_i = i;
tree->Fill();
}
tree->Print();
tree->Write();
delete hfile;
}