[boost] [defer] - comments?

Anyone had a play with the defer library in the vault and want to comment on its usefulness? It clearly shares much in common with the asio Dispatcher concept but with the freedom to define more general Dispatchers. (e.g. 'Create thread per callback' and 'Dispatch Callback via Message Pump', both of which violate the specific guarantees of the asio Dispatcher concept, that the callback occur in a thread that has called asio::demuxer::run().) One potential application for defer would be in conjunction with asio, creating the thread(s) which call demuxer::run() in a succinct form. Cheers Simon