Hello!

I'm coming to this project from rust-lang/rust#99389 , where some stricter checks of creation of uninitialized data is being tested out, and the crates.io version of this crate ran into the checks. It looks like 0.2.0 on crates.io has out of date dependencies, eventually leading to an out of date smallvec.

I tested the proposed change on master, and it ran fine, so the only thing that's needed is a new release to be made.