Struct Task 

pub struct Task { /* private fields */ }

A spawned task or stream. Dropping it detaches — the work keeps running and its callback keeps firing. Keep it to cancel when whatever the callback would write is going away.

Deliberately !Send: the callback it controls lives in the spawning thread’s registry, so a handle taken to another thread could only cancel that thread’s tasks instead.

Implementations

impl Task

pub fn cancel(self)

Drops the callback, so anything the worker still posts is discarded. The thread is not interrupted — std::thread has no way to do that — but a spawn_stream worker polling Emitter::is_cancelled can stop on its own.

pub fn is_pending(&self) -> bool

Whether the callback is still registered — the value has yet to arrive, or the stream is still open.