How would you refactor this add function? (In c++)

double add(double a, double b ) \{ return a+b; \} double add(double a, double b, double c){ return a+b+c; double add(double a, double b, double c, double d ) \{ return a+b+c+d; double add(double a, double b, double c, double d, double e) \{ return a+b+c+d+e; double add(double a, double b, double c, double d, double e, double f) \{ return a+b+c+d+e+f; s