syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"ty::Infer(_)"}]}
source_snippet:             ty::Infer(_) => panic!("upvar_tys called before capture types are inferred"),
context_before:             ty::Tuple(tys) => tys,
context_after:             ty => panic!("Unexpected representation of upvar types tuple {:?}", ty),