{"ast_node_type":"variable","tokens":[{"end":56,"kind":"keyword","start":0,"text":"if"}]}
                    if let hir::ByRef::Yes(mutability) =
                    // ergonomics, in which case `pat.hir_id` will be the id of the subpattern.
                        self.cx.typeck_results().deref_pat_borrow_mode(place.place.ty(), subpattern)