#include "../Eigen/Core"

#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
#define CV_QUALIFIER const
#else
#define CV_QUALIFIER
#endif

using namespace Eigen;

void foo(CV_QUALIFIER Matrix3d &m) {
  Block<Matrix3d, 3, 3> b(m.block<3, 3>(0, 0));
  EIGEN_UNUSED_VARIABLE(b);
}

int main() {}