/** @file list3901.cpp */
/** Listing 39-1. The Definition of generate_id’s Members in generate_id.cpp */
class generate_id
{
public:
  generate_id() : counter_(0) {}
  long next();
private:
  short counter_;
  static short prefix_;
  static long int const max_counter_ = 32767;
};

// Switch to random-number as the initial prefix for production code.
// short generate_id::prefix_(static_cast<short>(std::rand()));
short generate_id::prefix_(1);
long const generate_id::max_counter_;

long generate_id::next()
{
  if (counter_ == max_counter_)
    counter_ = 0;
  else
    ++counter_;
  return prefix_ * (max_counter_ + 1) + counter_;
}