[boost] [futures] composite or

Hi, I was looking at the futures implementation in the boost vault. It looks very promising, I must say. One of the open issues however is thread cancellation which I imagine will be important in the case of the "or" futures group. Has there been any progress on this front? One of the coolest things about boost libraries has been the gradual improvement of legacy C/C++ code by non-invasive means. I can't imagine solving this problem without invasive means (or traditionally undesirable means, i.e. something like thread->die()). I'm not saying that its non-invasive or nothing, but there are people smarter than me working on this problem! Thanks in advance, Sohail