#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+a;
#else
b = argc>1 ? VectorXf(2*a) : VectorXf(a+a);
#endif
}