[$] Zapping pointers out of thin air

Paul McKenney gave a presentation at Kangrejos this year that wasn't (directly)related to Rust. Instead, he spoke about the work he has been doing in concertwith many other contributors on improving the handling of subtle concurrencyproblems in C++.Although he cautioned that his talk was only an overview, and not asubstitute for reading the relevant papers, he hoped that the things the C++community is working on would be of interest to the Rust developers present aswell, and potentially inform future work on the language. McKenney's talk was,as is his style, full of subtle examples of weird multithreaded behavior.Interested readers may wish to refer tohis slides in an attempt to follow along.