weird.nim(12, 9) Error: undeclared field: 'PK_INT'

weird.nim

type
  TNodeKind = enum PK_EMPTY, PK_INT, PK_STRING

  TNode = object
    case kind: TNodeKind
    of PK_EMPTY: nil
    of PK_INT: int_val: int
    of PK_STRING: str_val: string

template new_node(kind: TNodeKind, expr): TNode {.immediate.} =
  var result {.gensym.}: TNode
  result.kind = kind
  case kind:
  of PK_EMPTY: nil
  of PK_INT: result.int_val = expr
  of PK_STRING: result.str_val = expr
  result

when isMainModule:
  var t1, t2 : TNode
  t1.kind = PK_INT
  t1.int_val = 3
  t2.kind = PK_STRING
  t2.str_val = "3"
  let t3 = new_node(PK_INT, 3)
  echo "Hey!"