// chset.h
// Definition of chset class

#ifndef CHSETH
#define CHSETH

#include <iostream.h>
#include "pmglobs.h"

class chset {
   private:
      char* set;   // a pointer to a space yet to be allocated
   public:
      chset(const char* s=NULL);  // constructor
      ~chset();    // destructor
      bool in(char ch) const;  // char ch is part of set set.
      void incl(char ch);      // include the char ch in set set.
      void operator<(char ch); // overload operator <
      friend chset operator+(const chset& c1, const chset& c2);
      friend ostream& operator<<(ostream& co, const chset& c);
      chset& operator=(const chset& c);  // overlaod assignment operator =
}; // end of class chset definition.

#endif