templates & calculator

#include <iostream>
#include <cstdlib>

template <typename T>
int add(const T &a, const T &b) {
    return a + b;
}

template <typename T>
int sub(const T &a, const T &b) {
    return a - b;
}

template <typename T>
int mul(const T &a, const T &b) {
    return a * b;
}

template <typename T>
int div(const T &a, const T &b) {
    return a / b;
}

template <typename T, T (*F)(const T&, const T&)>
T calc1(T a, T b) {
    return F(a, b);
}

enum {
    ADD,
    SUB,
    DIV,
    MUL
};

template <typename T, int I=ADD>
T calc2(T a, T b) {
    return (I==ADD) ? (a+b) : ((I==SUB) ? (a-b) : ((I==MUL) ? (a*b) : (a/b)));
}

int main(void) {
    using namespace std;

    cout << calc1<int, add>(2, 4) << endl;
    cout << calc2<float, SUB>(3.0f, 1.0f) << endl;

    return EXIT_SUCCESS;
}