#![feature(dropck_parametricity)]
#![cfg_attr(test, feature(test))]
+#![allow(deprecated)]
+
extern crate alloc;
use std::cell::{Cell, RefCell};
/// than objects without destructors. This reduces overhead when initializing
/// plain-old-data (`Copy` types) and means we don't need to waste time running
/// their destructors.
+#[unstable(feature = "rustc_private",
+ reason = "Private to rustc", issue = "0")]
+#[rustc_deprecated(since = "1.6.0-dev", reason =
+"The reflection-based arena is superseded by the any-arena crate")]
pub struct Arena<'longer_than_self> {
// The heads are separated out from the list as a unbenchmarked
// microoptimization, to avoid needing to case on the list to access a head.