#![feature(allocator_api)]
#![feature(box_syntax)]
+#![feature(cow_is_borrowed)]
+#![feature(const_cow_is_borrowed)]
#![feature(drain_filter)]
#![feature(exact_size_is_empty)]
#![feature(new_uninit)]
#![feature(slice_ptr_get)]
#![feature(split_inclusive)]
#![feature(binary_heap_retain)]
+#![feature(deque_range)]
+#![feature(inplace_iteration)]
+#![feature(iter_map_while)]
+#![feature(int_bits_const)]
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};