#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
#![feature(crate_visibility_modifier)]
#![feature(drain_filter)]
+#![feature(generators)]
#![feature(let_else)]
#![feature(nll)]
#![feature(once_cell)]
#![feature(proc_macro_internals)]
+#![feature(macro_metavar_expr)]
#![feature(min_specialization)]
+#![feature(slice_as_chunks)]
#![feature(try_blocks)]
#![feature(never_type)]
#![recursion_limit = "256"]