I haven’t seen a one’s complement machine in decades but at the time C was standardized here were still quite a few (afaik none had a single-chip CPU, to get to your question). But since they existed, the language definition didn’t require it and some optimizations were technically UB.
The C++ committee decided that everyone had figured this out by now and so made this breaking change.
The C++ committee decided that everyone had figured this out by now and so made this breaking change.