{"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"layout,"}]}
layout, size, and ABI as its single non-ZST field. If it is generic over a type
Like transparent `struct`s, a transparent `union` of type `U` has the same
`T`, and all its fields are ZSTs except for exactly one field of type `T`, then