Haha. Thanks for writing it. I appreciate your and every leftpad porter's effort. :-) It makes for a perfect little dependency test with a standardized name. (Standardized up to /left[_-]?pad/i.) When a language doesn't have a leftpad package, I go looking for a concise way to make terminal text bold, which takes more time.

Plus, seeing code like https://github.com/colinrymer/leftpad.ex/blob/8d2230bf094eed... is just fun:

  defmodule Leftpad do
  
    @moduledoc """
    Remembering `String.rjust/3` can be difficult, so Leftpad provides you
    another way to easily left pad/right justify your UTF-8 encoded binaries.
    """
  
    @doc ~S"""
    Provides basically the same functionality as [`String.rjust/3`](http://elixir-lang.org/docs/stable/elixir/String.html#rjust/3)
    ## Examples
        iex> Leftpad.pad("foo", 5)
        "  foo"
        iex> Leftpad.pad("foobar", 6)
        "foobar"
        iex> Leftpad.pad("1", 2, ?0)
        "01"
    """
    @spec pad(string :: String.t, count :: non_neg_integer, char :: char) :: String.t
    def pad(string, count, char \\ 32), do: String.rjust(string, count, char)
  end

Look at that one line doing all the work, and even it delegates it to another function.

why not:

    defdelegate pad(string, count, char \\ 32), to: String, as: :rjust

Ha! I just found this the other day and thought it was for real, lol. I wasn't actually looking for leftpad, of course, but, well done!