1 #include "../Eigen/Core" 2 3 using namespace Eigen; 4 5 #ifdef EIGEN_SHOULD_FAIL_TO_BUILD call_ref(Ref<VectorXf> a)6void call_ref(Ref<VectorXf> a) { } 7 #else call_ref(const Ref<const VectorXf> & a)8void call_ref(const Ref<const VectorXf> &a) { } 9 #endif 10 main()11int main() 12 { 13 VectorXf a(10); 14 call_ref(a+a); 15 } 16