copy_site(IScalar<T>& d, int isite, const IScalar<T1>& s1)
copy_site(ILattice<T,N>& d, int isite, const IScalar<T1>& s1)
copy_site(IScalar<T>& d, int isite, const IScalar<T1>& s1){  d.elem() = s1.elem();}