copy_site(d.elem(), isite, s1.elem());
copy_site(d.real(), isite, s1.real()); copy_site(d.imag(), isite, s1.imag());
copy_site(RScalar<T>& d, int isite, const RScalar<T1>& s1){  copy_site(d.elem(), isite, s1.elem());}