Eigen const TensorMap

Consider the following (working) snippet:

Eigen::ArrayXd x (8);
x << 1, 2, 3, 4, 5, 6, 7, 8;
Eigen::TensorMap<Eigen::Tensor<double, 2>> y (x.data(), 2, 4);

This is also works:

const Eigen::ArrayXd const_x = x;
const Eigen::Map<const Eigen::ArrayXXd> z (const_x.data(), 2, 4);

I'm trying to figure out why I can't do this though:

const Eigen::TensorMap<const Eigen::Tensor<double, 2>> const_y (const_x.data(), 2, 4);

I'm using Eigen 3.3.3 (also tried 3.3.4)