`try_from` is now stable.
#![recursion_limit = "256"]
#![warn(rust_2018_idioms, trivial_casts, trivial_numeric_casts)]
#![feature(crate_visibility_modifier)]
-#![feature(try_from)]
// FIXME: switch to something more ergonomic here, once available.
// (currently there is no way to opt into sysroot crates w/o `extern crate`)
// error-pattern:yummy
#![feature(box_syntax)]
#![feature(rustc_private)]
-#![feature(try_from)]
#![allow(clippy::missing_docs_in_private_items)]
// FIXME: switch to something more ergonomic here, once available.