{"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":"fcx:"}]}
        fcx: &'a FnCtxt<'a, 'tcx>,
    struct UnsafeInferVarsVisitor<'a, 'tcx> {
        res: &'a mut UnordMap<ty::TyVid, (HirId, Span, UnsafeUseReason)>,