6 ms·

One thing to note is that it is not guaranteed that values are ever dropped. In rust, it is "safe" to leak memory (it wasn't possible to make it unsafe in rust)

• zozbot123 8y ago
  AIUI, this should only come up in rare cases, mostly involving RC cycles. The "should" proviso is there because the operation of "forgetting" that a value has to be dropped (thus de-facto leaking it) is in fact allowed in Safe Rust, and it's not immediately clear to me where that might come up in practice.
  • lilyball 8y ago
    std::mem::forget() is allowed in Safe Rust specifically because it's always possible to reconstruct it safely using Rc. As for where it comes up, it's usually because you're handing ownership of the memory to something outside of Rust's normal memory management. In most cases you'll be using a higher-level API like Box::into_raw(), but if you look at the implementation of that you'll see it uses mem::forget() internally.