And yet by "pulling in the JVM" (which is a rounding error in 2017), it's remarkably easy to generate a proxy that actually works as people expect a TCP proxy to work. This doesn't even so much as wait for connections to drain before terminating. This "300-line snippet" (which is reliant on Asio, which is not 300 lines by any stretch) is, as near as I can tell, not viable in real-world conditions and the spirited defenses of it that put it as competitive with real-world, battle-tested solutions are profoundly weird.

(Similarly, because I don't really care about JVM versus not, HAProxy--which I'd probably use for something like this because I have better things to do with my programming time--is 90Kloc because it has stuff to do and does it right. Simple is only better if simple can actually get the job done.)

Not sure if the 300 loc is really a fair comparison, as it is using ASIO (https://think-async.com/) under the covers, which is far more than 300 loc.