How to sort container with std::optional type?

Question

Looking for a way to sort an optional container Like the following...

#include <optional>
#include <vector>

using optional = std::optional<int>;
std::vector<optional> cont;

int main()
{
   auto min_iter = std::min_element(cont.begin(), cont.end());
   std::sort(cont.begin(), cont.end());
}