It took me a few tries to convince myself, but I think I agree with you that Rust can do this with lifetimes and unsafe. Importantly, the unsafe is self-contain

It took me a few tries to convince myself, but I think I agree with you that Rust can do this with lifetimes and unsafe. Importantly, the unsafe is self-contained, can be reliably generated by macros or codegen, and the end user doesn't have to muck with it.