text: void
  shiftview(const Arg *arg)
  {
  	Arg shifted;
  	unsigned int seltagset = selmon->tagset[selmon->seltags] & ~SPTAGMASK;
  	if (arg->i > 0) // left circular shift
  		shifted.ui = (seltagset << arg->i)
  		   | (seltagset >> (NUMTAGS - arg->i));
  	else // right circular shift
  		shifted.ui = seltagset >> -arg->i
  		   | seltagset << (NUMTAGS + arg->i);
  
  	view(&shifted);
  }
  