[uecker]

> C (where the safe subset is effectively empty),

Well, Fil-C and also Cheri show that C is a language that can be implemented with perfect memory safety for 99.9% of the language. This is not true for every language but is also not an accident in C. But also with the typical implementations of C such as clang and gcc you can essentially get spatial memory easily by using safe abstractions.

[dwattttt]

Very explicitly making a silly point; a rock is 100% memory safe.

The serious point: I care about whether the program I write aborts regularly, whether due to a Rust panic or a capability violation.

[uecker]

Regarding the silly point: Fil-C is less of a rock than Safe Rust as everything in C just works.

I am not sure about what you mean by "aborts regularly". After a memory safety issue, I think one usually wants to abort quickly and not do anything else in the program as the program state is confused, so running specific sanitizers in trapping mode together with coding abstractions that avoid unchecked raw pointer access you can write spatially memory safe code in C without a problem. But yes, sometimes you may want to continue running, but this is much harder and needs a careful design of the system anyway, also in other languages.