// Source: "Software Design ...", John A Robinson, Newnes, 2004, page 159.
// Program to calculate average mark in a course mark database.
// Along the way, derived types, inheritance and polymorphism are illustrated.
#include <iostream>
using namespace std;
#include "student.h"

int main(int argc, char **argv)
	{
	software_design software_design;
	if (argc != 2)
		{
		cout << "Usage: average filename\n";
		return(-1);
		}
	if (software_design.load_data(*(argv+1)) < 0)
		{
		cout << "Error while loading data\n";
 	return(-1);
		}
	software_design.work_out_marks();
	cout << "Average was " << software_design.average_mark() << '\n';
	return(0);
	}