Tuple assignment to singleton type field

[Per Östlund]

Currently it's not possible to assign to a field of a singleton type with a function returning a tuple:

uniontype UT
  record R
    Integer x;
  end R;
end UT;

function f
  input output UT ut;
algorithm
  // Doesn't work:
  (ut.x, ...) := tuple_f(...);

  // Workaround:
  (tmp_x, ...) := tuple_f(...);
  ut.x := tmp_x;
end f;

[Per Östlund]

Test script