#![feature(fmt_internals)]
#![feature(hashmap_internals)]
#![feature(is_sorted)]
-#![feature(iter_nth_back)]
#![feature(iter_once_with)]
#![feature(pattern)]
#![feature(range_is_empty)]
#![feature(test)]
#![feature(trusted_len)]
#![feature(try_trait)]
-#![feature(reverse_bits)]
#![feature(inner_deref)]
#![feature(slice_internals)]
#![feature(slice_partition_dedup)]