#include "../Eigen/Core"

using namespace Eigen;

int main(int argc, char **) {
  VectorXf a(10), b(10);
#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
  b = argc > 1 ? 2 * a : -a;
#else
  b = argc > 1 ? 2 * a : VectorXf(-a);
#endif
}