[Discuss-gnuradio] Using Eigen C++ template library in GNURADIO

[Nasi]

Dear members,

does anyone know how to use Eigen C++ template library in GNURADIO?

my OS is Ubuntu 16.04 lts.
gnuradio version 3.7.10,

I can use it separately as c++ library by adding these lines:

#include <eigen3/Eigen/Core>
#include <eigen3/Eigen/QR>
#include <eigen3/Eigen/Dense>

...
VectorXcf fftshiftXcf(VectorXcf x, int NFFT);
...
//----------------------------------------------------------

however, in gnuradio project, I get the error:

error: ‘VectorXcf’ does not name a type
VectorXcf fftshiftXcf(VectorXcf x, int NFFT);

-- 
NE