"When you are using Undefined Behavior, you are not using C." Yes you are using C when you're using undefined behavior. It's one of the cornerstones of C's "de

"When you are using Undefined Behavior, you are not using C." Yes you are using C when you're using undefined behavior. It's one of the cornerstones of C's "design." The standard is poorly defined enough that different people building C compilers will come up with their own interpretation of what specific, legal, C statements mean. These are statements used in real projects that also compile with real compilers. The massive problems that resulted led to static analyzers and compiler checks for undefined behavior. Plus, people recommending you avoid it wherever possible for predictability, safety, and security. It is legal C, though. Whereas, in languages like Pascal or Ada, you could express similar operations with their semantics making it totally clear what you could expect. They'll either not compile or include runtime checks to avoid similar problems wherever possible. C's designers just didn't give a shit: they were using what modifications of unsafe BCPL they could to squeeze max performance & memory utilization out of a PDP-11. Wirth's Modula-2 at least gave a clean language with many checks & sanity by default that you could selectively turn off if absolutely necessary. Not C, though. So, it's legal, real C designed without safety, clear semantics, and so on. Different projects implement "real C" differently due to unclear semantics. Different, broken executions result.