No, sorry, in case I wasn't clear, I was talking about manual deallocation. I wasn't talking about a garbage collector. You still allocate and free cells. Here'

No, sorry, in case I wasn't clear, I was talking about manual deallocation. I wasn't talking about a garbage collector. You still allocate and free cells. Here's an example of what I am talking about: https://docs.rs/generational-arena https://docs.rs/generational-arena If you're implementing a tracing garbage collector you obviously don't need any such counters to detect use-after-frees. This is clearly a different compromise entirely to the one made by tracing garbage collection. I'm actually not sure how you confused the two.