> or _when_ undefined behavior is our friend. (emphasis mine) I think this is the key point a lot of responses are missing. It's not that undefined behavior is

> or _when_ undefined behavior is our friend. (emphasis mine) I think this is the key point a lot of responses are missing. It's not that undefined behavior is innately good or bad. It's that it leaves wiggle room that can potentially be exploited for good while being too rigid may not always be the best long-term strategy. I used to think of code as something that should live forever and compile/run for all time without change. Over time, I've come to realize that just as spoken languages evolve, so do our programming languages. To run/understand code written 2 decades ago, we often have to use compilers/interpreters from that era. I doubt that will change even with extremely rigid language specifications.