[otabdeveloper2]

The phrase 'undefined behavior' only makes sense in the context of an ISO standard.

For any particular combination of compiler, OS and computer architecture there are no 'undefined behaviors'; you only care about the concept if you want portability to a different compiler/OS/architecture.

So the idea that C++ sucks because of 'undefined behavior', so let's use some random language without an ISO standard or any portability guarantees at all is completely and utterly insane.