Set operator-(const Set & ) ;

Set Set::operator -(const Set & a)
    {
         int dif,i,j,k;// some handy variables
         Set f; // the object who's gonna be returned by the function
         f.size=0;// setting the size to 0 for now 
         for(i=0;i<size;i++)
        {  
            dif=0;
            for(j=0;j<a.size;j++)
            {      
                if(ptr[i]==a.ptr[j])
                    ++dif;
            }
         if(dif==0) 
             f.ptr[f.size++]=ptr[i]; //if an element wasn't found,in the    //other set , assign it to the f object .
        }
            return f;
    }

#ifndef SET_H
#define SET_H

#include <iostream>

using std::ostream;
using std::istream;


class Set
{
    friend ostream &operator<<( ostream &, const Set & );
    friend istream &operator>>( istream &, Set & );
    friend Set intersection(const Set & ,const Set & );
    friend Set reunioun(const Set & , const Set & );
    
    

public:

    Set( int = 10 ) ; // default constructor.
                          
    Set( const Set & )  ; // copy constructor
    ~Set() ;          // destructor
    int getSize() const ; // returns # of elements
    const Set &operator=( const Set & ); // assignment operator overloading
    bool operator==( const Set & ) const;  // equality operator overloading

   bool operator!=( const Set &right ) const  // != operator
      { return ! ( *this == right ); }


    int   &operator[](   int   );                // overloading [] subscript
    const   int  &operator[](  int  )  const ;   // =====/ / / ==== for const objects  


  Set operator-(const & Set); // Here the compiler shows errors

     
    static int  getSetCount();         //  returns the # objects instantiated
    
    // some set operations
    bool apartenenta(int ) ; 
    bool incluziunea  (const Set & ) const ; 
    bool egalitatea() ; 
    

    

private:
        int  size;  // the size of vector
        int  *ptr;  // pointer to the first element of the vector
        static int  count;   // it retaines the # of objects instantiated

Set operator-(const & Set);

Set operator-(const Set&);