Discord.SortedSet.size

You're seeing just the function size, go back to Discord.SortedSet module for more information.

size(set)

size(set :: t()) :: non_neg_integer() | Discord.SortedSet.Types.common_errors()

Get the size of a SortedSet

This function follows the standard Elixir naming convention, size/1 take O(1) time as the size is tracked with every addition and removal.