Earlier quoted context omitted.
> For example, the way signed and unsigned numbers are defined in the C standard What do you mean?
Presumably something like the representation of signed numbers being implementation defined (instead of two's complement as is virtually always the case nowadays).
I know this doesn't address the point about the C standard itself, but:
• GCC and Clang both accept the -fwrapv argument, causing the compiler to guarantee that signed overflow will wrap, like in Java
• The latest C++ standard mandates that signed integer types use two's complement representation (signed overflow remains undefined behaviour)