C++ debugging ostreams

helpme.hpp

// for cerr debugging, overloads for vector, list, set
template <class T>
std::ostream& operator<< (std::ostream& out, const std::vector<T>& v) {
  if ( !v.empty() ) {
    out << "vector[";
    for (T item : v) {
      out << item;
      out << ", ";
    }
    out << "\b\b]";
  }
  return out;
}
template <class T>
std::ostream& operator<< (std::ostream& out, const std::list<T>& v) {
  if ( !v.empty() ) {
    out << "list[";
    for (T item : v) {
      out << item;
      out << ", ";
    }
    out << "\b\b]";
  }
  return out;
}
template <class T>
std::ostream& operator<< (std::ostream& out, const std::set<T>& v) {
  if ( !v.empty() ) {
    out << "set[";
    for (T item : v) {
      out << item;
      out << ", ";
    }
    out << "\b\b]";
  }
  return out;
}
template <typename T1, typename T2>
std::ostream& operator<< (std::ostream& out, const std::pair<T1, T2>& v) {
  out << "pair(";
  out << v.first;
  out << ", ";
  out << v.second;
  out << ")";
  return out;
}