//: C15:Instrument3.cpp
// Late binding with the virtual keyword
#include <iostream.h>

enum note { middleC, Csharp, Cflat }; // Etc.

class Instrument {
public:
  virtual void play(note) const {
    cout << "Instrument::play" << endl;
  }
};

// Wind objects are Instruments
// because they have the same interface:
class Wind : public Instrument {
  public:
    // override interface function:
    void play(note) const {
      cout << "Wind::play" << endl;
    }
};

void tune(Instrument& i) {
  // ...
  i.play(middleC);
}

int main() {
  Wind flute;
  tune(flute); // Upcasting
} ///:~