update for libs team changes

Author: apasel422

text/0000-collection-recovery.md

@@ -5,8 +5,7 @@
 
 # Summary
 
-Add element-recovery methods to the set types in `std`. Add key-recovery methods to the map types
-in `std` in order to facilitate this.
+Add element-recovery methods to the set types in `std`.
 
 # Motivation
 
@@ -87,83 +86,21 @@ Add the following element-recovery methods to `std::collections::{BTreeSet, Hash
 ```rust
 impl<T> Set<T> {
     // Like `contains`, but returns a reference to the element if the set contains it.
-    fn element<Q: ?Sized>(&self, element: &Q) -> Option<&T>;
+    fn get<Q: ?Sized>(&self, element: &Q) -> Option<&T>;
 
     // Like `remove`, but returns the element if the set contained it.
-    fn remove_element<Q: ?Sized>(&mut self, element: &Q) -> Option<T>;
+    fn take<Q: ?Sized>(&mut self, element: &Q) -> Option<T>;
 
     // Like `insert`, but replaces the element with the given one and returns the previous element
     // if the set contained it.
     fn replace(&mut self, element: T) -> Option<T>;
 }
 ```
 
-In order to implement the above methods, add the following key-recovery methods to
-`std::collections::{BTreeMap, HashMap}`:
-
-```rust
-impl<K, V> Map<K, V> {
-    // Like `get`, but additionally returns a reference to the entry's key.
-    fn key_value<Q: ?Sized>(&self, key: &Q) -> Option<(&K, &V)>;
-
-    // Like `get_mut`, but additionally returns a reference to the entry's key.
-    fn key_value_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<(&K, &mut V)>;
-
-    // Like `remove`, but additionally returns the entry's key.
-    fn remove_key_value<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)>;
-
-    // Like `insert`, but additionally replaces the key with the given one and returns the previous
-    // key and value if the map contained it.
-    fn replace(&mut self, key: K, value: V) -> Option<(K, V)>;
-}
-```
-
-Add the following key-recovery methods to `std::collections::{btree_map, hash_map}::OccupiedEntry`:
-
-```rust
-impl<'a, K, V> OccupiedEntry<'a, K, V> {
-    // Like `get`, but additionally returns a reference to the entry's key.
-    fn key_value(&self) -> (&K, &V);
-
-    // Like `get_mut`, but additionally returns a reference to the entry's key.
-    fn key_value_mut(&mut self) -> (&K, &mut V);
-
-    // Like `into_mut`, but additionally returns a reference to the entry's key.
-    fn into_key_value_mut(self) -> (&'a K, &'a mut V);
-
-    // Like `remove`, but additionally returns the entry's key.
-    fn remove_key_value(self) -> (K, V);
-}
-```
-
-Add the following key-recovery methods to `std::collections::{btree_map, hash_map}::VacantEntry`:
-
-```rust
-impl<'a, K, V> VacantEntry<'a, K, V> {
-    /// Returns a reference to the entry's key.
-    fn key(&self) -> &K;
-
-    // Like `insert`, but additionally returns a reference to the entry's key.
-    fn insert_key_value(self, value: V) -> (&'a K, &'a mut V);
-
-    // Returns the entry's key without inserting it into the map.
-    fn into_key(self) -> K;
-}
-```
-
 # Drawbacks
 
 This complicates the collection APIs.
 
-The distinction between `insert` and `replace` may be confusing. It would be more consistent to
-call `Set::replace` `Set::insert_element` and `Map::replace` `Map::insert_key_value`, but
-`BTreeMap` and `HashMap` do not replace equivalent keys in their `insert` methods, so rather than
-have `insert` and `insert_key_value` behave differently in that respect, `replace` is used instead.
-
 # Alternatives
 
 Do nothing.
-
-# Unresolved questions
-
-Are these the best method names?