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From: Frank Mori Hess (fmhess_at_[hidden])
Date: 2008-05-25 16:51:37

On Sunday 25 May 2008 14:02, Peter Dimov wrote:
> Here's one way:
> future<T> ft;
> for( int i = 0; i < n; ++i )
> {
> ft = ft || async( f, i );
> }
> T t = ft.get();

That reminds me, I've been so focused on trying to make future_select work
with heterogeneous input futures, that I neglected the homogeneous case.
That is, future_select() always returns a future<void> even when all the
input futures have the same type. And after all, maybe supporting the
homogeneous case is good enough. For example, in my use case I've already
taken care to type-erase the method requests in the schedulers down to a
uniform type, because the scheduler needs to store them in a container

So the only other thing I'd need is some kind of explicit future container
that can be re-used to "wait for any" repeatedly without rebuilding the
entire set of futures each time. Maybe something with a queue-like

template<typename T>
class future_selecter
        future<T> front();
        void pop();
        void push(const future<T> &f);

where the future returned by front() would have the value from the next
future in the future_selector to become ready. pop() would discard the
completed future previously being returned by front(), so front() can
return a new future corresponding to the next one to complete.

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