E.g., String class, with underlying array on heap.

class String
{
public:
   String(); // Default constructor
   String(const char p[]); // Simple constructor
   String(const String& right); // Copy constructor
   ~String(); // Destructor
   String& operator=(const String& right); // Assignment operator
   String& operator+=(const String& right);
   int length() const;
   char& operator[](int index);
   char operator[](int index) const;
private:
   char* buffer;
   int len;
};