xtensor_8_N_8.hpp

template <class F, class... CT>
class xfunction_stepper
{
public:

    using xfunction_type = xfunction<F, CT...>;

    using value_type = typename xfunction_type::value_type;
    using reference = typename xfunction_type::value_type;
    using pointer = typename xfunction_type::const_pointer;
    using size_type = typename xfunction_type::size_type;
    using difference_type = typename xfunction_type::difference_type;

    template <class... St>
    xfunction_stepper(const xfunction_type* func, St&&... st) noexcept;

    void step(size_type dim, size_type n = 1);
    void step_back(size_type dim, size_type n = 1);
    void reset(size_type dim);
    void reset_back(size_type dim);

    void to_begin();
    void to_end(layout_type l);

    reference operator*() const;

private:

    template <std::size_t... I>
    reference deref_impl(std::index_sequence<I...>) const;

    const xfunction_type* p_f;
    std::tuple<typename std::decay_t<CT>::const_stepper...> m_st;
};