Comment by jcalvinowens

That's pretty silly IMHO, it should be incredibly obvious to anybody who is ever in a position to port code to a machine with non-8-bit-bytes that there will be dragons there. It also requires including limit.h which you might not otherwise need.

It's just not a realistic edge case, the machines like this are either antiquated or are tiny microcontrollers that can't practically run a POSIX OS. Very little code in the real world is generic enough to be useful in that environment (a good example might be a fixed point signal processing library).

There is no assertion in the entire Linux kernel that CHAR_BIT is eight, despite that assumption being hardcoded in many places.