Or when you enable optimizations and since accessing an object with invalid state is UB, the compiler helpfully decides it is now permitted to format your hard

Or when you enable optimizations and since accessing an object with invalid state is UB, the compiler helpfully decides it is now permitted to format your hard drive. https://gcc.gnu.org/legacy-ml/gcc/2016-02/msg00381.html https://gcc.gnu.org/legacy-ml/gcc/2016-02/msg00381.html "The fact is, undefined compiler behavior is never a good idea. Not for serious projects."