SIunits.Conversions.to_unit1(r);
The function call
"Conversions.to_unit1(r)" returns r
with unit="1".
  Modelica.SIunits.Velocity v = {3,2,1};
  Real direction[3](unit="1") = to_unit1(v);   // Automatically vectorized call of to_unit1
function to_unit1 extends Modelica.SIunits.Icons.Conversion; input Real r "Real number"; output Real result(unit = "1") "Real number r with unit=\"1\""; end to_unit1;