To be honest the implementation looks surprisingly readable… at least compared to other horrors like the standard library implementation.

While there are some new rules regarding arguments naming, the new syntax doesn’t feel more complex than the default lambda syntax.

So all in all I would say the most horrifying thing here is the fact that the language allows such extensions in the first place ;)

Once you strip out all the helper code for tuples and args, it's really not the worst. Made sense to me on the first read. Sensible naming and not that much metaprogramming indirection going on, thank god.

Or maybe I am too brainwashed by C++ at this point.