Class remove

example/tutorial/appendix_mpl.cpp:309–314

template <typename Sequence, typename T>
struct remove {
    using type = decltype(hana::filter(
        hana::to_tuple(Sequence{}),
        hana::not_equal.to(hana::type_c<T>)
    ));
};

template <typename Sequence, typename Pred>
struct remove_if {