pub fn block_on<F>(f: F) -> Result<<F as Future>::Item, <F as Future>::Error> where
Run a future to completion on the current thread.
This function will block the caller until the given future has completed. Any tasks spawned onto the default executor will also be run on the current thread, but they may not complete before the function returns. Instead, once the starting future has completed, these other tasks are simply dropped.
LocalPool if you need finer-grained control over