{"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"//"}]}
                        // patterns. If we're here we can assume this is a box pattern.
                        // The only legal patterns of type `Box` (outside `std`) are `_` and box
                        let subst_ty = substs.at(Interner, 0).assert_ty_ref(Interner).clone();