Sigil_r example not working as shown in the official docs

Looks like it works with the old charlist syntax but not with the new:

iex(1)> sigil_r(<<"foo">>, 'i')
~r/foo/i
iex(2)> sigil_r(<<"foo">>, ~c"i")
** (ArgumentError) errors were found at the given arguments:

  * 1st argument: not an iodata term

    (stdlib 5.1.1) :binary.list_to_bin({:sigil_c, [delimiter: "\"", line: 2], [{:<<>>, [line: 2], ["i"]}, []]})
    (elixir 1.15.6) expanding macro: Kernel.sigil_r/2
    iex:2: (file)

I guess the syntax has been changed to the new one without checking if it works. Filing an issue here could be a good starting point: GitHub - elixir-lang/elixir-lang.github.com: Website for Elixir · GitHub

You are right, it should be:

sigil_r(<<"foo">>, [?i])

Would you like to submit a PR to the docs or shall I update it?

Please, do it if you can.