#include <iostream>
#include <utility>
#include <array>

template <typename... Args>
void foo (Args&&... args) {
    const auto v = {args...};
    for (auto x : v) std::cout << x << ' ';     std::cout << '\n';
}

template <typename> struct Foo;

template <std::size_t... Is>
struct Foo<std::index_sequence<Is...>> {
    template <typename Container>  // *** Modified
    static void execute (const Container& v, void (*f)(decltype(v[Is])&...)) {
        f(v[Is]...);
    }
};

template <std::size_t N>
void fooArray (const std::array<int, N>& a) {
    Foo<std::make_index_sequence<N>>::execute(a, foo);
}

int main() {
    fooArray<6>({0,1,2,3,4,5});
}