{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"self.demand_coerce(idx,"}]}
                    self.demand_coerce(idx, idx_t, index_ty, None, AllowTwoPhase::No);
                    // two-phase not needed because index_ty is never mutable
                    self.select_obligations_where_possible(|errors| {