Does GreenNode actually use tagged pointers for children?

[szmarczak]

syntax.md

To more compactly store the children, we box both interior nodes and tokens, and represent Either<Arc<Node>, Arc<Token>> as a single pointer with a tag in the last bit.

However

https://github.com/rust-analyzer/rowan/blob/fe2e4a7059e1fb8961b92e9d7738844faad7d675/src/green/node.rs#L25-L53

In particular

static_assert!(mem::size_of::<GreenChild>() == mem::size_of::<usize>() * 2);

type Repr = HeaderSlice<GreenNodeHead, [GreenChild]>;

pub struct GreenNode {
    ptr: ThinArc<GreenNodeHead, GreenChild>,
}

It doesn't look like it does what the docs are saying.