I'm only speaking for my personal preferences here. My two problems with undefined behavior is that 1) it is not always obvious that your program is guilty of

I'm only speaking for my personal preferences here. My two problems with undefined behavior is that 1) it is not always obvious that your program is guilty of undefined behavior and 2) when a C program contains undefined behavior the compiler can generate surprising machine code. I don't have any problem with 8/0 being undefined mathematically, but I do have a problem with a C compiler generating code that will delete my hard drive if it ever occurs (an unlikely but theoretically possible for a conforming C compiler). INT_MAX + 1 is problematic because most people expect wrap around (and in fact they may be using a compiler that does this). It's more problematic because UINT_MAX + 1 does get wrap around. And finally there's a bunch of difficult to remember auto integer conversion rules. Taken together it's not surprising that many people will find it difficult to determine if their integer usage is correct. One solution is of course to use a safer language than C (where I unfortunately have to end up). But I personally object to the idea that you have to have undefined behavior in order to get the performance of C (waiting to see how the development of languages like Rust goes to determine if I'm right).