coin bank

gistfile1.cpp

template <int64_t V>
class coin {
public:
    coin() : num {0} {}
    coin(coin const &) = default;
    explicit coin(int64_t n) : num {n} {}
    coin & operator=(coin const &) = default;
    void add(coin const & o) {
        num += o.num;
    }
    void remove(coin const & o) {
        num -= o.num;
    }
    int64_t count() {
        return num;
    }
    void set(int64_t n) {
        num = n;
    }
private:
    int64_t num;
};
typedef coin<1> pennies;
typedef coin<5> nickels;
typedef coin<10> dimes;
typedef coin<25> quarters;
typedef coin<50> half_dollars;
typedef coin<100> dollar_coins;
template <typename...C>
class coin_bank {
public:
    template <typename T, typename...R>
    void add(T v, R...r) {
        std::get<T>(coins).add(v);
        add(std::forward<R>(r...));
    }
    void add() {}

    template <typename T, typename...R>
    void remove(T v, R...r) {
        std::get<T>(coins).subtract(v);
        subtract(std::forward<R>(r...));
    }
    void remove() {}

    template <typename T, typename...R>
    void set(T v, R...r) {
        std::get<T>(coins) = v;
        set(std::forward<R>(r...));
    }
    void set() {}

    template <typename T>
    T get() {
        return std::get<T>(coins);
    }
private:
    std::tuple<C...> coins;
};
typedef coin_bank<pennies, nickels, dimes, quarters, half_dollars, dollar_coins> american_coin_bank;

int main() {
    american_coin_bank wut;
    wut.add(pennies {5}, nickels {7});
    wut.remove(pennies {2});
    wut.set(nickels {5});
    std::cout << "pennies: " << wut.get<pennies>().count() << endl;
    std::cout << "nickels: " << wut.get<nickels>().count() << endl;
}