defmodule RC do
  def dict_create(dict_impl \\ Map) do
    d = dict_impl.new                   #=> creates an empty Dict
    d1 = Dict.put(d,:foo,1)
    d2 = Dict.put(d1,:bar,2)
    print_vals(d2)
    print_vals(Dict.put(d2,:foo,3))
  end

  defp print_vals(d) do
    IO.inspect d
    Enum.each(d, fn {k,v} -> IO.puts "#{k}: #{v}" end)
  end
end

IO.puts "< create Map.new >"
RC.dict_create
IO.puts "\n< create HashDict.new >"
RC.dict_create(HashDict)