Enum.uniq_by Counter

[kitplummer]

Maybe this is a dupe…

Getting duplicates instead of unique values

I know that uniq/1 & uniq_by/2 return a list of unique values, but what is the best way to get a list of duplicate values? I noticed that the code for uniq & uniq_by could easily collect a list of duplicates while unique values are collected; so I copied this code and modified it to return a tuple with a list of unique values and a list of duplicates. But have I missed some existing functionality to do this?