At the very least (sorry), these keywords are missing from the C++ default keyword list, and should be added:
int_least8_t int_least16_t int_least32_t int_least64_tI suppose whether you like your header (.h) files to be considered “C” or “C++” is a matter of individual choice, so I don’t think there’s anything more to do other than what @Ekopalypse has already indicated.