only clang (not gcc) ships ubsan with support for checking unsigned integer overflow. clang's ubsan does not enable it by default (it must be explicitly enabled

only clang (not gcc) ships ubsan with support for checking unsigned integer overflow. clang's ubsan does not enable it by default (it must be explicitly enabled). As a result, it's not clear that it's a false positive in the technical sense here (as one would need to enable checking for unsigned overflow explicitly).