I/O Manipulators with Parameters - 2

• Generic overload of output operator

template < class F > // function class
std::ostream& operator<< (std::ostream& os, F f) //  function object
{
  f(os); // apply f.operator() to os
  return os;
}

• Analogous generic overload of input operator

template < class F >
std::istream& operator>> (std::istream& is, F f)
{
  f(is);
  return is;
}