#include <cassert>
#include <type_traits>
#include <iostream>

template <typename T, typename... Args>
struct is_one_of;

template <typename T>
struct is_one_of<T> {
    static constexpr bool result = false;
};

template <typename T, typename... Args>
struct is_one_of<T, T, Args...> {
    static constexpr bool result = true;
};

template <typename T, typename K, typename... Args>
struct is_one_of<T, K, Args...> {
    static constexpr bool result = is_one_of<T, Args...>::result;
};



template <typename... List> struct type_list {
};



template <typename T, typename TypeList>
struct is_one_of_type_list;

template <typename T, typename... Args>
struct is_one_of_type_list<T, type_list<Args...>> {
    static constexpr bool result = is_one_of<T, Args...>::result;
};




template <typename T>
struct message
{
  T payload;
};


struct payload_ll_1{};
struct payload_ll_2{};
using ll_payload_list = type_list< payload_ll_1, payload_ll_2 >;

struct payload_ss_1{};
struct payload_ss_2{};
using ss_payload_list = type_list < payload_ss_1, payload_ss_2 >;


template <typename T>
void f( const message<T>& msg,
        typename std::enable_if<is_one_of_type_list<T, ll_payload_list>::result>::type* = 0) {
    std::cout << "I'm LL payload" << std::endl;
}

template <typename T>
void f( const message<T>& msg,
        typename std::enable_if<is_one_of_type_list<T, ss_payload_list>::result>::type* = 0) {
    std::cout << "I'm SS payload" << std::endl;
}


int main() {
    assert(is_one_of<int>::result == false);
    assert((is_one_of<int, int>::result == true));
    assert((is_one_of<int, int, char, double>::result == true));
    assert((is_one_of<int, char, int, double>::result == true));
    assert((is_one_of<int, char, double>::result == false));

    using MyTypeList = type_list<int, char, double>;
    assert((is_one_of_type_list<int, MyTypeList>::result == true));
    assert((is_one_of_type_list<float, MyTypeList>::result == false));


    message<payload_ll_1> ll_msg;
    f( ll_msg );

    message<payload_ss_1> ss_msg;
    f( ss_msg );
}