mrdocs::cast

template<
    class To,
    class From>
requires ( std::derived_from<std::remove_cvref_t<To>, std::remove_cvref_t<From>> )
[[nodiscard]]
std::remove_reference_t<To>&
cast(Polymorphic<From>& p);

template<
    class To,
    class From>
requires ( std::derived_from<std::remove_cvref_t<To>, std::remove_cvref_t<From>> )
[[nodiscard]]
std::remove_reference_t<To> const&
cast(Polymorphic<From> const& p);