#include "../Eigen/Core"
#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
#define CV_QUALIFIER const
#else
#define CV_QUALIFIER
#endif
using namespace Eigen;
void foo(float *ptr){
Map<CV_QUALIFIER MatrixXf>(ptr, 1, 1).coeffRef(0,0) = 1.0f;
}
int main() {}