Main.cc: In function ‘int main()’: Main.cc:12:42: error: no match for ‘operator/’ (operand types are ‘double’ and ‘std::ostream {aka std::basic_ostream}’) result = static_cast(a) / b / ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ std::cout << std::fixed << std::setprecision(9); ~~~ Main.cc:12:42: note: candidate: operator/(double, int) Main.cc:12:42: note: no known conversion for argument 2 from ‘std::ostream {aka std::basic_ostream}’ to ‘int’