next(isolation:)

Declaration

mutating func next(isolation actor: isolated (any Actor)?) async throws(Failure) -> Element?

Discussion

When next() returns nil, this signifies the end of the AsyncThrowingStream.

It is a programmer error to invoke next() from a concurrent context that contends with another such call, which results in a call to fatalError().

If you cancel the task this iterator is running in while next() is awaiting a value, the AsyncThrowingStream terminates. In this case, next() may return nil immediately, or else return nil on subsequent calls.