-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Christopher Kohlhoff
I've attached a quick and dirty futures implementation that I wrote last year to demonstrate how futures and asio might fit together. Unlike the various futures proposals that are around, I prefer to keep the producer and consumer interfaces separate. Hence I have promise<T> (producer interface) and future<T> (consumer interface) -- these names are borrowed from the Alice programming language.
Splitting promise from future seems like a good idea, it should make the future class in libpoet a little less confusing. One thing your code reminded me of is forwarding exceptions to the future, something I put off then completely forgot about in libpoet. Since I'm trying to provide an active function object that wraps an ordinary passive function, for the general case I would need to call something like your promise::fail() from a catch block that catches exceptions thrown by the passive function. Unfortunately, that would require something like a templated catch. It seems the best I can do is provide special handling for some particular type of exception, like a boost::shared_ptr<std::exception> and if the passive function throws anything else, it just gets forwarded to the future as something like a poet::unknown_exception. Frank