void f0() { std::cout << "f0" << std::endl; }
void f1(double p1) { std::cout << "f1" << std::endl; }
void f2(double p1, double p2) { std::cout << "f2" << std::endl; }
void f3(double p1, double p2, double p3) { std::cout << "f3" << std::endl; }
void f4(double p1, double p2, double p3, double p4) { std::cout << "f4" << std::endl; }