syntax_data: {"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// of `rustc_index::newtype_index!` means that `Option<Symbol>` only takes up 4 bytes,
context_before: /// (including hashing, equality, and ordering) operate on that index. The use
context_after: /// because `rustc_index::newtype_index!` reserves the last 256 values for tagging purposes.