The library only uses /Enum.case as a way of imitation. If there were first class support for case paths (enum key paths) in the language, I imagine we'd use \Enum.case.
To disambiguate between computed properties: \Enum.case as CasePath<Enum, Case>
To disambiguate from overloaded case names: \Enum.case(arg1:) vs. \Enum.case(arg2:)