Auto merge of #41437 - cuviper:remove-unstable-deprecated, r=alexcrichton

Remove items that are unstable and deprecated

This removes unstable items that have been deprecated for more than one cycle.

- Since 1.16.0, `#![feature(enumset)]`
    - All of `mod collections::enum_set`
- Since 1.15.0, `#![feature(borrow_state)]`
    - `cell::BorrowState`
    - `RefCell::borrow_state()`
- Since 1.15.0, `#![feature(is_unique)]`
    - `Rc::is_unique()` (made private like `Arc::is_unique()`)
- Since 1.15.0, `#![feature(rc_would_unwrap)]`
    - `Rc::would_wrap()`
- Since 1.13.0, `#![feature(binary_heap_extras)]`
    - `BinaryHeap::push_pop()`
    - `BinaryHeap::replace()`
- Since 1.12.0, `#![feature(as_unsafe_cell)]`
    - `Cell::as_unsafe_cell()`
    - `RefCell::as_unsafe_cell()`
- Since 1.12.0, `#![feature(map_entry_recover_keys)]`
    - `btree_map::OccupiedEntry::remove_pair()`
    - `hash_map::OccupiedEntry::remove_pair()`
- Since 1.11.0, `#![feature(float_extras)]`
    - `Float::nan()`
    - `Float::infinity()`
    - `Float::neg_infinity()`
    - `Float::neg_zero()`
    - `Float::zero()`
    - `Float::one()`
    - `Float::integer_decode()`
    - `f32::integer_decode()`
    - `f32::ldexp()`
    - `f32::frexp()`
    - `f32::next_after()`
    - `f64::integer_decode()`
    - `f64::ldexp()`
    - `f64::frexp()`
    - `f64::next_after()`
- Since 1.11.0, `#![feature(zero_one)]`
    - `num::Zero`
    - `num::One`

1 files changed, 1 insertions, 18 deletions

diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 69e5351cad5..38dc9145835 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -340,19 +340,6 @@ impl<T> Rc<T> {
         }
     }
 
-    /// Checks whether [`Rc::try_unwrap`][try_unwrap] would return
-    /// [`Ok`].
-    ///
-    /// [try_unwrap]: struct.Rc.html#method.try_unwrap
-    /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok
-    #[unstable(feature = "rc_would_unwrap",
-               reason = "just added for niche usecase",
-               issue = "28356")]
-    #[rustc_deprecated(since = "1.15.0", reason = "too niche; use `strong_count` instead")]
-    pub fn would_unwrap(this: &Self) -> bool {
-        Rc::strong_count(&this) == 1
-    }
-
     /// Consumes the `Rc`, returning the wrapped pointer.
     ///
     /// To avoid a memory leak the pointer must be converted back to an `Rc` using
@@ -532,11 +519,7 @@ impl<T: ?Sized> Rc<T> {
     ///
     /// [weak]: struct.Weak.html
     #[inline]
-    #[unstable(feature = "is_unique", reason = "uniqueness has unclear meaning",
-               issue = "28356")]
-    #[rustc_deprecated(since = "1.15.0",
-                       reason = "too niche; use `strong_count` and `weak_count` instead")]
-    pub fn is_unique(this: &Self) -> bool {
+    fn is_unique(this: &Self) -> bool {
         Rc::weak_count(this) == 0 && Rc::strong_count(this) == 1
     }