C++ async and futures in Mbed-os

it looks like C++ features like async programming can be used already, I have found Tests that make use of this extensions.
Can you recommend some readings about this or is there a tutorial for this? I have not played yet with this features, is it advisable to use them or is the overhead in std lib to much?

ok, it does not work. The async calls were used in the unit tests which run on a host system.