Ah, neat. It's relatively new—I've always rolled my own implementation whenever I needed it (it's super simple, which is why this library is 67 lines of impleme

Ah, neat. It's relatively new—I've always rolled my own implementation whenever I needed it (it's super simple, which is why this library is 67 lines of implementation, half being comments), but why roll your own when it's part of the (experimental) standard library?