template <typename T>struct reverse_range{private:T& x_;

public:
reverse_range (T& x): x_ (x) {}

auto begin () const -> decltype (this->x_.rbegin ())
{
return x_.rbegin ();
}

auto end () const -> decltype (this->x_.rend ())
{
return x_.rend ();
}
};

template <typename T>
reverse_range<T> reverse_iterate (T& x)
{
return reverse_range<T> (x);
}

std::vector<int> v = {1, 2, 3, 5, 7, 11};

for (auto x: reverse_iterate (v))
...;