#![feature(box_patterns)]
#![feature(core_intrinsics)]
#![feature(discriminant_kind)]
+#![feature(if_let_guard)]
#![feature(never_type)]
#![feature(extern_types)]
#![feature(new_uninit)]
#![feature(try_reserve)]
#![feature(try_reserve_kind)]
#![feature(nonzero_ops)]
+#![cfg_attr(bootstrap, allow(incomplete_features))] // if_let_guard
#![recursion_limit = "512"]
#[macro_use]