> I guess if one is always able to construct default values of T then this is not a problem. this is how go handles it; func do_thing(val string) (string, e

> I guess if one is always able to construct default values of T then this is not a problem. this is how go handles it; func do_thing(val string) (string, error) is expected to return `"", errors.New("invalid state")` which... sucks for performance and for actually coding.