Re: [boost] [futures] untyped_promise or future<void>

From: Peter Dimov (pdimov_at_[hidden])
Date: 2007-03-24 13:29:12

Braddock Gaskill wrote:

> Except for that pesky "cancelation handler" callback, a cancel() call
> is the same as set_exception(future_cancel()) on the promise.  Thus
> it kind of breaks the promise/future split.

In my proposed model, cancel() doesn't place an exception into the future. 
It's a consumer-side operation, used to indicate that the consumer is no 
longer interested in the outcome. set_exception( fork_canceled() ) is called 
by the producer if the cancel() call succeeds in canceling the task before 
it has finished.