// compile-flags: -Z unstable-options #![feature(rustc_private)] #![deny(rustc::potential_query_instability)] extern crate rustc_data_structures; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; fn main() { let mut x = FxHashMap::::default(); for _ in x.drain() {} //~^ ERROR using `drain` can result in unstable for _ in x.iter() {} //~^ ERROR using `iter` for _ in Some(&mut x).unwrap().iter_mut() {} //~^ ERROR using `iter_mut` for _ in x {} //~^ ERROR using `into_iter` }