Function main

Examples/NoModules/Appendix A/ExA_06/ExA_06.cpp:8–13

double power(double x, int n);  // Redundant declaration (harmless)

int main()
{
  for (int i{ -3 }; i <= 3; ++i)    // Calculate powers of 8 from -3 to +3
    std::cout << std::format("{:10}\n", power(8.0, i));
  std::cout << std::endl;
}

double power(double x, int n)   // A first definition
{