Not sure, the qsort is recursive and stack limitations were mentioned. But the point being that the reason they don't use their library functions because it's a

Not sure, the qsort is recursive and stack limitations were mentioned. But the point being that the reason they don't use their library functions because it's a constrained environment. Maybe they could permit some of their sort library functions to be used in such a constrained environment, sure. Don't need rust to do that, just need to be happy that the implementation is suitable for purpose. Which they would have to do regardless of what language and runtime they were using.