It looks like Facebook's `folly` library had an implementation of coroutines available in their experimental directory since mid-2018. There was still some evol

It looks like Facebook's `folly` library had an implementation of coroutines available in their experimental directory since mid-2018. There was still some evolution going on after it was pushed though (and it seems like there still is today). Not sure if that helps the argument that this has been around for "years" (since it's still in the experimental directory), but I guess there were some libraries trying to accomplish this. https://github.com/facebook/folly/tree/master/folly/experimental/coro https://github.com/facebook/folly/tree/master/folly/experime...