On 2/8/07, Matthias Troyer <troyer@phys.ethz.ch> wrote:
... A possible solution would indeed be to have a simple combine method for those accumulators where this is possible, and to work on a general solution later. This would immediately give the combine functionality to a part of the user community, while for the more demanding applications we have to wait.
Matthias
That sounds reasonable. Two things: 1. It might be a good idea to decide now on a concept for Combinable Accumulator so people don't run off and make ad-hoc ones. The syntax acc1(acc2) seems nice and has the most obvious semantics of the options I can think of. On the other hand, acc1 = combine(acc1, acc2); might be more generic. 2. Since some accumulators would have to be implemented differently to be combinable, would it make sense to use the dependency mechanism to request a combinable accumulator? That is, a syntax like accumulator_set<double, stats<tag::mean, tag::moment<2>, tag::combinable>
acc; If possible, this would be a nice syntax to request that every accumulator be combinable.
—Ben