On Friday 23 May 2008 10:50, Johan Torp wrote:
Yes, I'm thinking of a passive function which doesn't have an internal thread associated with it. One that is evaluated lazily as soon as someone is interested in it.
I think this could be very useful, do you?
Hmm, so it does seem that I would need something like what you've been suggesting to convert my scheduler over to waiting on futures instead of relying directly on signals/slots. Or, at least I would minimally need to be able to construct a future<X> from and future<Y> where X and Y are unrelated types by specifying a passive conversion function. So for example, when future<Y> fut_y; becomes ready, the future<X> would become ready with the value returned by conversion_function(fut_y.get()). The more general solution that accepts multiple arguments would be like future_barrier, except it would accept an additional first argument that is the conversion function, and it would return a future<R> where the value R for the returned future is obtained by calling the conversion function with all the values from the input futures. So it might look something like R combining_function(const T1 &t1, const T2 &t2, ..., const TN &tn); future<T1> f1; future<T1> f2; //... future<T1> fN; future<R> result = future_combining_barrier(&combining_function, f1, f2, ..., fN);