Unordered batch subscribe.

unordered_batch_subscribe.swift

extension Sequence where Element: Publisher {
	func bufferedSubscribe(by size: Int) -> AnyPublisher<[Element.Output], Element.Failure> {
		publisher
			.buffer(size: .max, prefetch: .byRequest, whenFull: .dropOldest) // Since we’re
			// buffering up to `Int.max` elements _by request_ — to avoid flooding the buffer — ,
			// `BufferingStrategy.dropOldest` or `.dropNewest` likely work equally well here.
			.flatMap(maxPublishers: .max(size)) { $0 }
			.collect(size)
			.eraseToAnyPublisher()
	}
}