#![feature(iter_advance_by)]
#![feature(slice_group_by)]
#![feature(slice_partition_dedup)]
-#![feature(vec_spare_capacity)]
#![feature(string_remove_matches)]
#![feature(const_btree_new)]
#![feature(const_default_impls)]
#![feature(const_trait_impl)]
#![feature(const_str_from_utf8)]
#![feature(nonnull_slice_from_raw_parts)]
+#![feature(panic_update_hook)]
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};