// ------------------------------------------------------------------------
// Ordered base class -- An abstract class
// A. Fischer  June 8, 1998                               file: ordered.hpp
//
#pragma once

#include <limits.h>
#include <iostream>
using namespace std;

// ------------------------------------------------------------------------
class Ordered {
  public:
    virtual ~Ordered(){}
    virtual KeyType key() const                         =0;
    virtual bool    operator <  (const KeyType&) const  =0;
    virtual bool    operator == (const KeyType&) const  =0;
};