Method begin

cpp/nd/array.hpp:245–259

        dict dict_value(int64_t index) const override;

        iterator begin() const override
        {
            if constexpr (impl::has_data_member_function_v<I> && !impl::is_scalar_v<I> &&
                          !impl::has_is_none_member_variable_v<I>) {
                auto sh = shape();
                auto subvolume = std::accumulate(sh.begin() + 1, sh.end(), 1L, std::multiplies<int64_t>()) *
                                 nd::dtype_bytes(impl_.dtype());
                auto d = std::span<const uint8_t>(impl_.data().data(), subvolume);
                return iterator(data_iterator(impl_.owner(), d, icm::shape(sh.begin() + 1, sh.end()), impl_.dtype()));
            } else if constexpr (impl::has_begin_member_function_v<I>) {
                return iterator(impl_.begin());
            } else {
                throw invalid_operation("begin() method is not implemented for this array.");
            }
        }

        iterator end() const override
        {