1 #include "../Eigen/Core" 2 3 using namespace Eigen; 4 main(int argc,char **)5 int main(int argc,char **) 6 { 7 VectorXf a(10), b(10); 8 #ifdef EIGEN_SHOULD_FAIL_TO_BUILD 9 b = argc>1 ? 2*a : -a; 10 #else 11 b = argc>1 ? 2*a : VectorXf(-a); 12 #endif 13 } 14