There's a library for it: https://github.com/sourcegraph/conc
But this goes to one of the things I've been kind of banging on about languages, which is that if it's not in the language, or at least the standard library right at the beginning, sometimes it almost might as well not exist. Sometimes a new language can be valuable, even if it has no "new" language features, just to get a chance to reboot the standard library it has and push for patterns that older languages are theoretically capable of, but they just don't play well with any of the libraries in the language. Having it as a much-later 3rd party library just isn't good enough.
(In fact if I ever saw a new language start up and that was basically its pitch, I'd be very intrigued; it would show a lot of maturity in the language designer.)