syntax_data: {"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":")"}]}
source_snippet: ) -> Result<(), ErrorGuaranteed> {
context_before:     used_to_be_allowed: Option<FutureCompatOverlapErrorKind>,
context_after:     let impl_polarity = tcx.impl_polarity(impl_def_id.to_def_id());