Class String Public Interface

// comparison operators
int operator == (const String& S1, const String& S2);
int operator != (const String& S1, const String& S2);
int operator <  (const String& S1, const String& S2);
int operator <= (const String& S1, const String& S2);
int operator >= (const String& S1, const String& S2);
int operator >  (const String& S1, const String& S2);

// I/O operators (these will become friends during implementation)
ostream& operator << (ostream& os, const String& S);
istream& operator >> (istream& is, String& S);