If anyone does have this case it's two distinct functions in my mind the first function does the comparison and returns the warning You can then assert and typ

If anyone does have this case it's two distinct functions in my mind the first function does the comparison and returns the warning You can then assert and type against the warning function, the printing function you could only assert against with output buffering or something like that but in my mind that's less likely to go wrong anyway Keep your type system simple, custom types beyond in built primitives cause head aches imo