> And although the support for specific width integer types is optional, what isn't optional is uintmax_t.

> Given that no platform has native support for 128bit integer this implies you think platforms should support it despite the fact that they don't.

> And if they do, then uint128_t now becomes the largest supported int meaning that now uintmax_t must also be at least 128bits width (the impact of which is catastrophic).

This is no longer true since C23/C++23, see

https://cplusplus.github.io/LWG/issue3828

https://www.open-std.org/jtc1/sc22/WG14/www/docs/n2888.htm

Thanks,

F.v.S.