> - Forces you to consider error handling If you use the result. Its easy to overlook that some more procedural functions might return only an optional err val

> - Forces you to consider error handling If you use the result. Its easy to overlook that some more procedural functions might return only an optional err value. See also stuff like append sometimes mutates and returns a reference to a slice with the same backing array, and sometimes returns a slice with a different backing array. Nothing going to remind you you forgot to copy before returning.