Index sequnece example

gistfile1.cpp

// Example only shows expansion logic, not perfect forwarding
template<class F, class T, size_t... I>
auto unpack(F f, T t, std::index_sequence<I...>) {
    return f(std::get<I>(t)...);
}

template<class F, class T>
auto tuple_eval(F f, T arg) {
    return unpack(f, args, std::make_index_sequence<std::tuple_size<T>::value>());
}