A bit belated answer, but here it is...
I've done POCO local socket support quite some time ago, see this
blog post. I may include it in Sockets library which we plan to extract out of Net and propose for standardization.
As for async I/O, there's been many requests for Poco::ASIO over last years. Admittedly, we are in a "deer in headlight" mode not knowing how to do that right. I don't think anybody does, even C++ standards committee is uncertain
on what is behind std::async (dilemma: thread or something else behaving "as if it was" thread). Given the current state of flux
in CPU/GPU world, we have a big mess and nobody really knows how to do it right, let alone do it portable. It seems that a combination of threads, async I/O and coroutines with a dose of work stealing
currently fits the bill of proper solution. How does one reconcile all that and create a comprehensible model is another story. According to Microsoft, turning C++ in Erlang direction
is the answer.
Don't lose hope, we'll do something for sure but can't promise any deadlines there.