///////    File: Refstr.C ///////

#include "Refstr.h"

Refstr::Cell::Cell( char *s )
{    str = new char[strlen(s)+ 1];
     strcpy(str, s);
     cnt = 1;
}

int Refstr::cmp(const Refstr& s) const
{    if ( s.ptr == ptr )
        return(0);
     else
        return(strcmp(ptr->str, s.ptr->str));
}

void Refstr::display() { cout << ptr->str << "\n"; }

Refstr::~Refstr()
{  cout << "~Refstr " << ptr->str
        << " cnt=" << ptr->cnt << "\n";
   if ( --ptr->cnt == 0 )
       delete ptr;    // invokes ~Cell automatically
}

Refstr::Refstr(char *s)
{   ptr = new Cell(s);  }

Refstr& Refstr::OP = (const Refstr& s)
{     if (this == &s || ptr == s.ptr )
         return(*this);
      cout << ptr->str << " = " << s.ptr->str<< "\n";
      if ( --ptr->cnt == 0 ) delete ptr;
      ptr = s.ptr;
      ptr->cnt++;
      return(*this);
}

// copy constructor

Refstr::Refstr(const Refstr& s)
{     ptr = s.ptr;
      ptr->cnt++;
}