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cancel safety

Whether stopping a future halfway can lose data or leave things half-done.

Dropping a future cancels it at its current await point; a cancel-safe operation (e.g. mpsc::Receiver::recv) loses nothing if cancelled there, which matters inside select! loops.

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Examples

  • timeout(Duration::from_millis(100), book_van()) drops the future at 100 ms, so its BayReservation guard's Drop runs and releases the bay, but the van is never booked.

See also

structured concurrency Future trait drop
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