Point being, _kst_'s comment of "I don't know of any compilers that provide them" is correct - there are few if any compilers that actually have actual extended

Point being, _kst_'s comment of "I don't know of any compilers that provide them" is correct - there are few if any compilers that actually have actual extended integer types, and thus introducing such in compilers might be non-trivial, and plenty of code may exist under the assumption that they don't exist and thus could break (things like integer promotion rules, _Generic, varargs; and also intmax_t is of mention as it must be at least as wide as any supported standard or extended integer type (which is also why clang/gcc __int128 doesn't qualify as an integer type as per the standard))