Enum.count/2 is more efficient than Enum.filter/2 |> Enum.count/1.

# this should be refactored
[1, 2, 3, 4, 5]
|> Enum.filter(fn x -> rem(x, 3) == 0 end)
|> Enum.count()

# to look like this
Enum.count([1, 2, 3, 4, 5], fn x -> rem(x, 3) == 0 end)

The reason for this is performance, because the two separate calls to Enum.filter/2 and Enum.count/1 require two iterations whereas Enum.count/2 performs the same work in one pass.

This task rewrites the code when mix recode runs with autocorrect: true.