ctai_string_from_int_2.cpp

template <int value, typename sign_str, char ...chars>
struct string_from_int_impl<value, sign_str, false, string<chars...>>
{
    using type = typename string_from_int_impl<
            value/10,
            sign_str,
            value/10 == 0,
            string<value % 10 + '0', chars...>>::type;
};