#include <TROOT.h>
#include <TTree.h>
#include <TFile.h>
#include <vector>
using namespace std;

int main() { 
 
  TFile *f = new TFile("outfile.root","RECREATE");
  TTree *t = new TTree("tree","description");
  
  vector<float> *b_some_branch = new vector<float>;
  
  t->Branch("some_branch",&b_some_branch);

  for(int i=0; i<10; i++) {
    
    b_some_branch->clear();
    b_some_branch->push_back(float(i));
    t->Fill();
    
  }
  
  f->cd();
  f->Write();
  f->Close();

  return 0;
  
}