> I still haven’t figured how to map things like cached_results: HashMap<u32, Result<String, Error>> into the fallible function model. In this case, there’s no

> I still haven’t figured how to map things like cached_results: HashMap<u32, Result<String, Error>> into the fallible function model. In this case, there’s no function that could be fallible. Oh you can definitely make a generically cached version of a fallible function, by either: - Re-throwing the same exception at future lookups, or a clone if preferred (requires storing the exception) - Treating the exception case as an uncacheable value (always logically consistent with caches that allow items to disappear at any time)