I'm trying to understand the difference between folly::coro::timeout vs folly::corotimeoutNoDiscard

I'm looking at the docs here: .h#L51

The docs are the same for both except for this line

The returned result is always that of the operation. In other words the result is never discarded, in contrast with timeout.

I don't understand what this means. Is it implying that if I use timeout API, the result may not be the operation result if it succeed within the timeout?

Would appreciate an example usage to understand the difference.