[hummingly]

When you call to_owned, it creates a Vec<u8>. This must then be truncated due to the call to into_boxed_slice. The documentation says this could potentially mean a re-allocation depending on the allocator. When this happens the old allocation needs to be dropped too. You could try using a different allocator but before this I would recommend to replace those two calls with Box::from(s.as_bytes()).

[skitter]

The vec already gets allocated with capacity == length

https://doc.rust-lang.org/nightly/src/alloc/slice.rs.html#16...