#ifndef GRADE_H
#define GRADE_H
#include <iostream> //for classes istream and ostream
#include <string>   //for class string
using namespace std;

class grade {
private:
	int i;   //in the range 0 to n-1 inclusive; 0 means F, 13 means A+

	static const size_t n {14}; //the number of possible grades
	static const string a[n];   //names of the grades: "F", "F+", ..., "A+"
public:
	grade(): i {0} {}   //Default constructor puts F into newborn object.
	grade(const string& s);

	grade& operator+=(int inc);
	operator int() const {return i;}

	friend ostream& operator<<(ostream& ost, const grade& g) {
		return ost << grade::a[g.i];
	}

	friend istream& operator>>(istream& ist, grade& g);
};

#endif