[masklinn]

As others have mentioned, Result is a sum type so you either have a T or an E, there's no situation in which you can get both or neither.

The second part is that it's reified as a single value, so it works just fine as a normal value e.g. you can map a value to a result, or put results in a map, etc... , language doesn't really care.

And then you can build fun utilities around it e.g. a transformer from Iterator<Item=Result<T, E>> to Result<Vec<T>, E> (iterates and collects values until it encounters an error, in which case it aborts and immediately returns said error).