SinglePublisherOperation is a subclass of Foundation's Operation that subscribes to a single publisher and reports its result.
open class AsynchronousOperation<Output, Failure: Error>: Operation { }
class SinglePublisherOperation<Upstream: SinglePublisher>: AsynchronousOperation<Upstream.Output, Upstream.Failure> { }The publisher is subscribed when the operation starts, and the operation completes when the uptream publisher completes:
let publisher = ... // some single publisher
let operation = publisher.makeOperation()
let queue = OperationQueue()
queue.addOperation(operation)To grab the result of the publisher from the operation, query the operation's result, of type Result<Output, Failure>:
if let result = operation.result {
// Operation is finished
} else {
// Operation is not finished, or cancelled
}See also TraitPublishers.AsOperation.