Pass by Const Reference

 void  pass_by_const_ref(const  int  &i)  {
     //  compilation  error  on  following  line
     i  =  4;
 }

 int  main()  {
     int  j  =  1;
     pass_by_const_ref(j);
     std::cout  <<  j  <<  std::endl;
 }