{"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"#[derive(Copy,"}]}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
/// can take arbitrary large values (and hence mustn't be used with `IndexVec`/`BitSet`).
pub(crate) struct EnumVariantContiguousIndex(usize);