[tsukikage]

We make a distinction between undefined and implementation defined behaviour for a reason. Saying that certain runtime behaviours result in malformed programs while being impractical to generate explicit checks for is not entirely crazy.

That said, I believe the set of undefined behaviours in our current standards is much, much too large - most of these should rightly be filed in the implementation-defined category instead. It is no longer the 70s and the very same modern compilers that perform more and more extreme optimisations year on year really do not need to account for a giant zoo of quirky experimental architectures; over the decades we've basically settled on a consensus on how pointers, integers, floating-point numbers etc ought to work.