Given the statement in the documentation that a blocking queued connection blocks until the slot returns, one would expect to be able to useQMetaObject:: invokeMethod to call a blocking connection to call a slot and get the return value (which one can't - for obvious reasons - do with a plain QueuedConnection).

This would be a useful technique to make synchronous cross-thread calls, and so I would really love to see it implemented. At minimum, though, it seems the documentation should explain this not-entirely-obvious limitation.