I was just going one step further due to my experience in proving correctness of algorithms in functional languages. You probably had on mind usual array safety

I was just going one step further due to my experience in proving correctness of algorithms in functional languages. You probably had on mind usual array safety checks and control flow stuff for which aspects were invented, I raised the bar a bit by pointing out that there are some fundamental issues which even super functional purists can't overcome, so the overall talk about code safety is kinda funny ;-) You will still crash Space Shuttle if you are running on Haskell, just in a different fashion than with C.