{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"if"}]}
                if !self_ty.is_fn_ptr() && self_ty.is_known_rigid() {
                // that it does *not* implement `FnPtr`.
                    ecx.probe_builtin_trait_candidate(BuiltinImplSource::Misc).enter(|ecx| {