#![feature(core_intrinsics)]
#![feature(dropck_parametricity)]
#![feature(fmt_internals)]
+#![feature(fused)]
#![feature(heap_api)]
#![feature(inclusive_range)]
#![feature(lang_items)]
#![feature(specialization)]
#![feature(staged_api)]
#![feature(step_by)]
-#![feature(unboxed_closures)]
#![feature(unicode)]
#![feature(unique)]
-#![feature(unsafe_no_drop_flag)]
+#![cfg_attr(stage0, feature(unsafe_no_drop_flag))]
#![cfg_attr(test, feature(rand, test))]
#![no_std]