fn register_ready_callback<F>(&mut self, _cb: F)
    where
        F: Fn() + Send + Sync + 'static,
    {
    }
/// Register callback to be invoked when an asynchronous operator becomes
/// ready.
///
/// This method should only be used for asynchronous operators (see
/// documentation for [`is_async`](`Self::is_async`) and
/// [`ready`](`Self::ready`)) in order to enable dynamic schedulers to
/// run async operators as they become ready without continuously
/// polling them.  It can be invoked at most once per operator; invoking
/// it more than once is undefined behavior.
///
/// Once the callback has been registered, the operator will invoke the
/// callback at every clock cycle, when the operator becomes ready.
/// The callback in invoked with at-least-once semantics, meaning that
/// spurious invocations are possible.  The scheduler must always check
/// if the operator is ready ro run by calling [`ready`](`Self::ready`)
/// and must be prepared to wait if it returns `false`.
Register callback to be invoked when an asynchronous operator becomes
ready.



Once the callback has been registered, the operator will invoke the
callback at every clock cycle, when the operator becomes ready.
The callback in invoked with at-least-once semantics, meaning that
spurious invocations are possible.
Register callback to be invoked when an asynchronous operator becomes ready . Once the callback has been registered the operator will invoke the callback at every clock cycle when the operator becomes ready . The callback in invoked with at - least - once semantics meaning that spurious invocations are possible .
fn register_ready_callback<F>(&mut self, _cb: F)
    where
        F: Fn() + Send + Sync + 'static,
    {
    }
fn register_ready_callback < F > ( & mut self , _cb : F ) where F : Fn ( ) + Send + Sync + ' static , { }
Register callback to be invoked when an asynchronous operator becomes
ready.
Register callback to be invoked when an asynchronous operator becomes ready .
&mut self
_cb
F