template <class C> 
constexpr auto size(const C& c) -> decltype(c.size())
{
    return c.size();
}

template <class C>
constexpr auto ssize(const C& c) 
    -> std::common_type_t<std::ptrdiff_t,
                          std::make_signed_t<decltype(c.size())>> {
    using R = std::common_type_t<std::ptrdiff_t,
                                 std::make_signed_t<decltype(c.size())>>;
    return static_cast<R>(c.size());
}

template <class T, std::size_t N>
constexpr std::size_t size(const T (&array)[N]) noexcept
{
    return N;
}

template <class T, std::ptrdiff_t N>
constexpr std::ptrdiff_t ssize(const T (&array)[N]) noexcept
{
    return N;
}