syntax_data: {"ast_node_type":"function","tokens":[{"end":60,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn with<R>(f: impl FnOnce(&mut HygieneData) -> R) -> R {
context_before:     #[inline]
context_after:         with_session_globals(|session_globals| f(&mut session_globals.hygiene_data.borrow_mut()))