C++20 - Shocking Examples of Undefined Behavior

The first example of UBE by Eric Muser, originally, is signed into the drawer floor combined with optimizer. Initially, it wasn't supposed to be an endless loop but as you can see here, it's not endless loop when it's compiled without optimizations. Next we have this article by Mohit Saini. Shocking examples of undefined behavior. They are not that shocking if you already know about UBE, but if it's your first encounter, boy, are you in for a surprise. And as usual, you shouldn't try too hard to make ugly things pretty. And this stuff is very often ugly.