That looks like Microsoft's new "async everywhere" approach to API design. It's probably a pretty good idea in concept, but I hope they don't expect C++ developers to actually write those awful nested lambda .then() blocks for what are conceptually sequential actions.
Sure, but is that much better? It reminds me of having to create named struct classes to simulate closures prior to C++11 lambdas. The language syntax just doesn't support that style of programming.
Is there a better approach available in C++? In other languages you'd use monads or other special compiler forms that can rewrite sequential looking code into the horrible multi-nested callback/error handling code it needs to be.
