# File lib/rbreadline.rb, line 1454
  def rl_overwrite_mode(count, key)
    if (!@rl_explicit_arg)
      _rl_set_insert_mode(@rl_insert_mode ^ 1, 0)
    elsif (count > 0)
      _rl_set_insert_mode(RL_IM_OVERWRITE, 0)
    else
      _rl_set_insert_mode(RL_IM_INSERT, 0)
    end
    0
  end