Auto merge of rust-lang#51079 - GuillaumeGomez:stabilize-entry-or-default, r=SimonSapin

Stabilize entry-or-default

Fixes rust-lang#44324.

cc @SimonSapin

Author: bors

src/doc/unstable-book/src/library-features/entry-or-default.md

@@ -2184,14 +2184,13 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
 }
 
 impl<'a, K: Ord, V: Default> Entry<'a, K, V> {
-    #[unstable(feature = "entry_or_default", issue = "44324")]
+    #[stable(feature = "entry_or_default", since = "1.28.0")]
     /// Ensures a value is in the entry by inserting the default value if empty,
     /// and returns a mutable reference to the value in the entry.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(entry_or_default)]
     /// # fn main() {
     /// use std::collections::BTreeMap;
     ///

src/liballoc/btree/map.rs

@@ -45,7 +45,6 @@
 #![feature(const_fn)]
 #![feature(core_intrinsics)]
 #![feature(drain_filter)]
-#![feature(entry_or_default)]
 #![feature(from_ref)]
 #![feature(fs_read_write)]
 #![feature(iterator_find_map)]

src/librustc/lib.rs

@@ -2161,14 +2161,13 @@ impl<'a, K, V> Entry<'a, K, V> {
 }
 
 impl<'a, K, V: Default> Entry<'a, K, V> {
-    #[unstable(feature = "entry_or_default", issue = "44324")]
+    #[stable(feature = "entry_or_default", since = "1.28.0")]
     /// Ensures a value is in the entry by inserting the default value if empty,
     /// and returns a mutable reference to the value in the entry.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(entry_or_default)]
     /// # fn main() {
     /// use std::collections::HashMap;
     ///
@@ -2184,7 +2183,6 @@ impl<'a, K, V: Default> Entry<'a, K, V> {
             Vacant(entry) => entry.insert(Default::default()),
         }
     }
-
 }
 
 impl<'a, K, V> OccupiedEntry<'a, K, V> {