program()
type
  File = record
    fd: Int
  end

  Stack#[T] = record
    items: ^T;
    top: Word
  end

var
  s: Stack#[File]
  f: File

proc push#[T](target: ^Stack#[T]; value: ^T)
begin
  target^.items := value;
  target^.top := target^.top + 1u
return

begin
  s.top := 0u;
  push#[File](@s, @f);
  assert(s.top = 1u);
  assert(s.items = @f)
end.