Slices in Rust are actually kinda similar to VLAs in C99, but usable in places other than aggregates, and use an additional word in pointers to them for the length, as a safety mechanism. You can even use slices as the last member of a struct, like VLAs, though they're not very ergonomic currently (you can only obtain references to them, as well as Boxes containing them, using "unsizing" coercion):
https://play.rust-lang.org/?version=stable&mode=debug&editio...