Wait for async logger queue to empty (without shutdown)

[yohayonyon]

Hi all,

Calling flush() on an async logger only flushes the sinks, but doesn't wait for the queue to be fully processed by the background thread.

Is there a way to block until the async queue is empty, without shutting down or stopping the logger?

Thanks!

[tt4g]

Currently not supported.
A PR that waits for asynchronous flushes has been merged (#3049), but there was a bug and it was reverted (#3235).