#![feature(const_swap)]
#![feature(const_trait_impl)]
#![feature(const_type_id)]
#![feature(const_type_name)]
#![feature(const_default_impls)]
#![feature(const_swap)]
#![feature(const_trait_impl)]
#![feature(const_type_id)]
#![feature(const_type_name)]
#![feature(const_default_impls)]