main.cpp

#include <iostream>
#include <string>

struct zero {};
struct one {};
struct two {};

template<typename T>
struct is_same;

template<>
struct is_same<std::tuple<zero>> {
    static bool check(int *p) {
        return *p == 0;
    }

    static zero cast(int *p) {
        return zero {};
    }
};

template<>
struct is_same<std::tuple<one>> {
    static bool check(int *p) {
        return *p == 1;
    }

    static one cast(int *p) {
        return one {};
    }
};

template<>
struct is_same<std::tuple<two>> {
    static bool check(int *p) {
        return *p == 2;
    }

    static two cast(int *p) {
        return two {};
    }
};

template<typename K, typename Q, typename ...Args>
struct is_same<std::tuple<K, Q, Args...>> {
    static bool check(int *p) {
        return is_same<std::tuple<K>>::check(p) && is_same<std::tuple<Q, Args...>>::check(p + 1);
    }
};



template<typename F>
struct f_info;

template<typename R, typename ...Args>
struct f_info<R(Args...)> {
    using return_type = R;
    using arguments = std::tuple<Args...>;
    using pointer_type = R (*)(Args...);
};

template<typename R, typename ...Args>
struct f_info<R(*)(Args...)> : f_info<R(Args...)> {};

template<typename R, typename ...Args>
void call_f(R (&f)(Args...), int *p) {
    f((is_same<std::tuple<Args>>::cast(p))...);
}

template<typename F>
bool try_call(F &f, int *p) {
    if (is_same<typename f_info<F>::arguments>::check(p)) {
        call_f(f, p);
        std::cout << "Called " << typeid(F).name() << std::endl;
        return true;
    } else {
        std::cout << "Error calling " << typeid(F).name() << std::endl;
        return false;
    }
}

template<typename F, typename Q, typename ...Args>
bool try_call(F &f, Q &q, Args&... a, int *p) {
    return try_call<F>(f, p) || try_call<Q, Args...>(q, a..., p);
}

void handler_a(two, two, two) {
    std::cout << "A" << std::endl;
}

void handler_b(two, two, zero) {
    std::cout << "B" << std::endl;
}

int main() {
    int a[] = { 2, 2, 0 };
    try_call(handler_a, handler_b, a);
    return 0;
}