typedef typename UnaryReturn<RComplex<T>, FnSum>::Type_t  Ret_t;  return Ret_t(sum(s1.real()), sum(s1.imag()));
return sum(s1.elem());
sum(const RComplex<T>& s1){  typedef typename UnaryReturn<RComplex<T>, FnSum>::Type_t  Ret_t;  return Ret_t(sum(s1.real()),	       sum(s1.imag()));}