d.elem() = where(a.elem(), b.elem(), c.elem());
d.real() = where(a.elem(), b.real(), c.real()); d.imag() = where(a.elem(), b.imag(), c.imag());
where(const RScalar<T1>& a, const RScalar<T2>& b, const RScalar<T3>& c){  typename BinaryReturn<RScalar<T2>, RScalar<T3>, FnWhere>::Type_t  d;  d.elem() = where(a.elem(), b.elem(), c.elem());  return d;}