#include <iostream>  //for the objects cin and cout
#include <cstdlib>   //for the macro EXIT_SUCCESS;
#include "grade.h"   //for class grade
using namespace std;

int main()
{
	try {
		const grade lowest;          //defaults to F
		cout << "The lowest grade is " << lowest << ".\n";
		cout << "Its numerical value is " << static_cast<int>(lowest)
			<< ".\n\n";

		const grade highest {"A+"};
		cout << "The highest grade is " << highest << ".\n";
		cout << "Its numerical value is " << static_cast<int>(highest)
			<< ".\n\n";

		const grade a[] {
			{"C"},   //Call constructor to construct a grade object.
			{"B+"},
			{"B"},
			{"B-"},
			{"A"}
		};
		const size_t n {size(a)};  //the number of elements in the array

		int sum {0};
		for (const auto& g: a) {   //g is each grade object in the array
			sum += g;          //means sum = sum + g.operator int();
		}

		grade average {lowest};
		average += sum/n;
		cout << "Average grade in array is " << average << ".\n";

		return EXIT_SUCCESS;
	}

	catch(invalid_argument& e) {
		cerr << e.what() << "\n";
		return EXIT_FAILURE;
	}

	catch (range_error& e) {
		cerr << e.what() << "\n";
		return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;   //Arrive here if no exceptions were thrown.
}