C++ Line Numbers?

#include <iostream>
#include "line_numbers.h"
using namespace std;

BEGIN_PROGRAM
case -20: cout << "Negative line numbers are AOKAY" << endl;
case -10: return 0;
case   0: cout << "Using 'line numbers' in C++" << endl;
case 100: cout << "Let's GOTO!" << endl;
case 200: GOTO(400);
case 300: cout << "Won't see this line!" << endl;
case 400: cout << "Hello World!" << endl;
case 450: cout << "Let's GOSUB!" << endl;
case 460: GOSUB(600);
case 470: cout << "Returned from sub!" << endl;
case 499: cout << "The end. Fin. Done." << endl;
case 500: return 0;
case 600: cout << "The subroutine!" << endl;
case 610: GOSUB(499);
case 620: GOSUB(-20);
case 700: return 0;
END_PROGRAM