How to call original synchronous method that has async overload in Xcode 13

Question

Recently switched to Xcode 13.

I have an AVAsset writer, and trying to call the method

writer.finishWriting()

which now has an async version, as well as the synchronous version.

I want to call the original synchronous version, but am getting the error:

"'async' call in a function that does not support concurrency. 
Add 'async' to function to make it asynchronous"

How can I call the original synchronous/pre-Xcode 13 version?

Answer 1

It looks like you forgot to add the trailing closure that the original function is expecting.

You want to use finishWriting(completionHandler:). The definition takes a trailing closure, completionHandler:

func finishWriting(completionHandler handler: @escaping () -> Void)

If you add the trailing closure:

writer.finishWriting {
    /* do stuff */
}

the code will compile as expected.