template< typename CompletionHandler> void post( CompletionHandler handler);
This function is used to ask the io_service to execute the given handler, but without allowing the io_service to call the handler from inside this function.
The io_service guarantees that the handler will only be called in a thread in which the run(), run_one(), poll() or poll_one() member functions is currently being invoked.
The handler to be called. The io_service will make a copy of the handler object as required. The function signature of the handler must be: