@RolandIllig I'm of the opinion that input sanitation should be done at the point where the input might go corrupt and not in some completely unrelated library. Such as ensuring that no string contains negative values. But yeah you can cast the input to ctype.h functions to
unsigned char... I'm not sure why, because if UB is invoked at that point, it means that all input data of the program is corrupt, which is the real problem.
