syntax_data: {"ast_node_type":"other","tokens":[{"end":29,"kind":"keyword","start":0,"text":"ty::Infer(_)"}]}
source_snippet:             ty::Infer(_) => {
context_before:             // prevention, which happens before this can be reached.
context_after:                 let cause = self.cause(ObligationCauseCode::WellFormed(None));