Roman_int.h

#ifndef ROMAN_INT_H_INCLUDED
#define ROMAN_INT_H_INCLUDED

#include <array>
#include <string>
#include <cctype>
#include <iostream>
#include <stdexcept>

//------------------------------------------------------------------------------

const int NO_VALUE = -1;

class Roman_int {
public:
    Roman_int() :roman("") {}

    int as_int() const;

    friend std::istream& operator>>(std::istream& is, Roman_int& r);
    friend std::ostream& operator<<(std::ostream& os, const Roman_int& r);
private:
    std::string roman;
};

bool isValidNumeral(std::string& numeral);
int valueof(const char c);

#endif // ROMAN_INT_H_INCLUDED