Subscribes to three additional publishers and invokes a closure upon receiving output from any of the publishers.
- iOS 13.0+
- macOS 10.15+
- Mac Catalyst 13.0+
- tvOS 13.0+
- watchOS 6.0+
- Xcode 11.0+
A second publisher to combine with this one.
A third publisher to combine with this one.
A fourth publisher to combine with this one.
A closure that receives the most recent value from each publisher and returns a new value to publish
A publisher that receives and combines elements from this publisher and three other publishers.
The combined publisher passes through any requests to all upstream publishers. However, it still obeys the demand-fulfilling rule of only sending the request amount downstream. If the demand isn’t
unlimited, it drops values from upstream publishers. It implements this by using a buffer size of 1 for each upstream, and holds the most recent value in each buffer. All upstream publishers need to finish for this publisher to finish. If an upstream publisher never publishes a value, this publisher neither produces any elements nor signals that publishing has completed. If any of the combined publishers terminates with a failure, this publisher also fails.