#include <iostream.h>

using namespace std;

class String {
	int len;
	char *chars;

public:
	String(const char *s) : len(strlen(s)), chars(new char[len]) {
		for (int i = 0; i < len; i++)
			chars[i] = s[i];
	}

	// default constructor
	String() : len(0), chars(new char[0]) {}

	// destructor
	virtual ~String() { delete[] chars; }

	// copy constructor
	String(const String &s) : len(s.len), chars(new char[len]) {
		for (int i = 0; i < len; i++)
			chars[i] = s.chars[i];
	}

	// assignment operator
	String & operator= (const String &s) {
		if (&s != this) {   // don't copy onto self
			delete[] chars;
			len = s.len;
			chars = new char[len];
			for (int i = 0; i < len; i++)
				chars[i] = s.chars[i];
		}
		return *this;
	}

	// print out a string
	void print() const {
		cout << '"';
		for (int i = 0; i < len; i++)
			cout << chars[i];
		cout << '"';
		cout << endl;
	}
};

int main(int argc, char *argv[]) {
	String s1;
	String s2 = s1;
	String s3 = "fred";
	s2 = s3;
	s2 = s2;	// nothing happens

	s1.print();
	s2.print();
	s3.print();

	return 0;
}