Correct. For example, if int is a 32-bit type (as it commonly is), then uint16_t will be promoted to signed int, and (uint16_t)0xFFFF * (uint16_t)0xFFFF will ca

Correct. For example, if int is a 32-bit type (as it commonly is), then uint16_t will be promoted to signed int, and (uint16_t)0xFFFF * (uint16_t)0xFFFF will cause signed overflow and trigger undefined behavior.