#![feature(bool_to_option)]
#![feature(box_patterns)]
#![feature(core_intrinsics)]
#![feature(bool_to_option)]
#![feature(box_patterns)]
#![feature(core_intrinsics)]
#![feature(discriminant_kind)]
#![feature(exhaustive_patterns)]
#![feature(if_let_guard)]
#![feature(discriminant_kind)]
#![feature(exhaustive_patterns)]
#![feature(if_let_guard)]