// check-pass use std::collections::HashMap; use std::sync::Mutex; fn i_used_to_be_able_to(foo: &Mutex>) -> Vec<(usize, usize)> { let mut foo = foo.lock().unwrap(); foo.drain().collect() } fn but_after_nightly_update_now_i_gotta(foo: &Mutex>) -> Vec<(usize, usize)> { let mut foo = foo.lock().unwrap(); return foo.drain().collect(); } fn main() {}