I haven't written any serious Rust in a while, but I assume there is some kind of lifetime annotation involved. The "objects" allocated in the arena have to be explicitly given the same lifetime as the arena itself. I have no idea how that looks syntactically.

There are several libraries for doing arena allocation in Rust, e.g. bumpalo: https://crates.io/crates/bumpalo , see the documentation for examples (it's quite easy to use and fits the borrow checker very well). The comments in here regarding Rust are somewhat misleading; Rust doesn't require unstable/nightly features to do this sort of stuff. What's unstable in Rust right now is a standardized interface for generically working with allocators (see https://github.com/rust-lang/rust/pull/157428 for the most recent progress), including support for the containers provided by the stdlib.