No, there are actually quite a few things CHERI does that aren't the borrow checker's job, and some things the borrow checker does that CHERI doesn't help with.

No, there are actually quite a few things CHERI does that aren't the borrow checker's job, and some things the borrow checker does that CHERI doesn't help with. In C and C++, if you write x[4] for an array with only 2 members, you get undefined behaviour. In Rust this causes a 'panic', but that isn't a 'borrow checker' thing, that's because in Rust all array accesses are bounds checked by default. You can do un-bounds checked array accesses in Rust, you can do bounds-checked accesses in C++ (for std::vector at least), it's just that the languages chose different defaults. One thing the borrow checker does is help write parallel code by stopping multiple threads writing to the same memory at the same time. CHERI doesn't stop that at all.