Rollup merge of #91593 - upsuper-forks:hashmap-set-methods-bound, r=dtolnay

Remove unnecessary bounds for some Hash{Map,Set} methods

This PR moves `HashMap::{into_keys,into_values,retain}` and `HashSet::retain` from `impl` blocks with `K: Eq + Hash, S: BuildHasher` into the blocks without them. It doesn't seem to me there is any reason these methods need to be bounded by that. This change brings `HashMap::{into_keys,into_values}` on par with `HashMap::{keys,values,values_mut}` which are not bounded either.

library/std/src/collections/hash/map.rs

@@ -349,6 +349,33 @@ pub fn keys(&self) -> Keys<'_, K, V> {
         Keys { inner: self.iter() }
     }
 
+    /// Creates a consuming iterator visiting all the keys in arbitrary order.
+    /// The map cannot be used after calling this.
+    /// The iterator element type is `K`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::collections::HashMap;
+    ///
+    /// let map = HashMap::from([
+    ///     ("a", 1),
+    ///     ("b", 2),
+    ///     ("c", 3),
+    /// ]);
+    ///
+    /// let mut vec: Vec<&str> = map.into_keys().collect();
+    /// // The `IntoKeys` iterator produces keys in arbitrary order, so the
+    /// // keys must be sorted to test them against a sorted array.
+    /// vec.sort_unstable();
+    /// assert_eq!(vec, ["a", "b", "c"]);
+    /// ```
+    #[inline]
+    #[stable(feature = "map_into_keys_values", since = "1.54.0")]
+    pub fn into_keys(self) -> IntoKeys<K, V> {
+        IntoKeys { inner: self.into_iter() }
+    }
+
     /// An iterator visiting all values in arbitrary order.
     /// The iterator element type is `&'a V`.
     ///
@@ -399,6 +426,33 @@ pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
         ValuesMut { inner: self.iter_mut() }
     }
 
+    /// Creates a consuming iterator visiting all the values in arbitrary order.
+    /// The map cannot be used after calling this.
+    /// The iterator element type is `V`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::collections::HashMap;
+    ///
+    /// let map = HashMap::from([
+    ///     ("a", 1),
+    ///     ("b", 2),
+    ///     ("c", 3),
+    /// ]);
+    ///
+    /// let mut vec: Vec<i32> = map.into_values().collect();
+    /// // The `IntoValues` iterator produces values in arbitrary order, so
+    /// // the values must be sorted to test them against a sorted array.
+    /// vec.sort_unstable();
+    /// assert_eq!(vec, [1, 2, 3]);
+    /// ```
+    #[inline]
+    #[stable(feature = "map_into_keys_values", since = "1.54.0")]
+    pub fn into_values(self) -> IntoValues<K, V> {
+        IntoValues { inner: self.into_iter() }
+    }
+
     /// An iterator visiting all key-value pairs in arbitrary order.
     /// The iterator element type is `(&'a K, &'a V)`.
     ///
@@ -555,6 +609,29 @@ pub fn drain_filter<F>(&mut self, pred: F) -> DrainFilter<'_, K, V, F>
         DrainFilter { base: self.base.drain_filter(pred) }
     }
 
+    /// Retains only the elements specified by the predicate.
+    ///
+    /// In other words, remove all pairs `(k, v)` such that `f(&k, &mut v)` returns `false`.
+    /// The elements are visited in unsorted (and unspecified) order.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::collections::HashMap;
+    ///
+    /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x*10)).collect();
+    /// map.retain(|&k, _| k % 2 == 0);
+    /// assert_eq!(map.len(), 4);
+    /// ```
+    #[inline]
+    #[stable(feature = "retain_hash_collection", since = "1.18.0")]
+    pub fn retain<F>(&mut self, f: F)
+    where
+        F: FnMut(&K, &mut V) -> bool,
+    {
+        self.base.retain(f)
+    }
+
     /// Clears the map, removing all key-value pairs. Keeps the allocated memory
     /// for reuse.
     ///
@@ -937,83 +1014,6 @@ pub fn remove_entry<Q: ?Sized>(&mut self, k: &Q) -> Option<(K, V)>
     {
         self.base.remove_entry(k)
     }
-
-    /// Retains only the elements specified by the predicate.
-    ///
-    /// In other words, remove all pairs `(k, v)` such that `f(&k, &mut v)` returns `false`.
-    /// The elements are visited in unsorted (and unspecified) order.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::collections::HashMap;
-    ///
-    /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x*10)).collect();
-    /// map.retain(|&k, _| k % 2 == 0);
-    /// assert_eq!(map.len(), 4);
-    /// ```
-    #[inline]
-    #[stable(feature = "retain_hash_collection", since = "1.18.0")]
-    pub fn retain<F>(&mut self, f: F)
-    where
-        F: FnMut(&K, &mut V) -> bool,
-    {
-        self.base.retain(f)
-    }
-
-    /// Creates a consuming iterator visiting all the keys in arbitrary order.
-    /// The map cannot be used after calling this.
-    /// The iterator element type is `K`.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::collections::HashMap;
-    ///
-    /// let map = HashMap::from([
-    ///     ("a", 1),
-    ///     ("b", 2),
-    ///     ("c", 3),
-    /// ]);
-    ///
-    /// let mut vec: Vec<&str> = map.into_keys().collect();
-    /// // The `IntoKeys` iterator produces keys in arbitrary order, so the
-    /// // keys must be sorted to test them against a sorted array.
-    /// vec.sort_unstable();
-    /// assert_eq!(vec, ["a", "b", "c"]);
-    /// ```
-    #[inline]
-    #[stable(feature = "map_into_keys_values", since = "1.54.0")]
-    pub fn into_keys(self) -> IntoKeys<K, V> {
-        IntoKeys { inner: self.into_iter() }
-    }
-
-    /// Creates a consuming iterator visiting all the values in arbitrary order.
-    /// The map cannot be used after calling this.
-    /// The iterator element type is `V`.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::collections::HashMap;
-    ///
-    /// let map = HashMap::from([
-    ///     ("a", 1),
-    ///     ("b", 2),
-    ///     ("c", 3),
-    /// ]);
-    ///
-    /// let mut vec: Vec<i32> = map.into_values().collect();
-    /// // The `IntoValues` iterator produces values in arbitrary order, so
-    /// // the values must be sorted to test them against a sorted array.
-    /// vec.sort_unstable();
-    /// assert_eq!(vec, [1, 2, 3]);
-    /// ```
-    #[inline]
-    #[stable(feature = "map_into_keys_values", since = "1.54.0")]
-    pub fn into_values(self) -> IntoValues<K, V> {
-        IntoValues { inner: self.into_iter() }
-    }
 }
 
 impl<K, V, S> HashMap<K, V, S>

library/std/src/collections/hash/set.rs

@@ -290,6 +290,28 @@ pub fn drain_filter<F>(&mut self, pred: F) -> DrainFilter<'_, T, F>
         DrainFilter { base: self.base.drain_filter(pred) }
     }
 
+    /// Retains only the elements specified by the predicate.
+    ///
+    /// In other words, remove all elements `e` such that `f(&e)` returns `false`.
+    /// The elements are visited in unsorted (and unspecified) order.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::collections::HashSet;
+    ///
+    /// let mut set = HashSet::from([1, 2, 3, 4, 5, 6]);
+    /// set.retain(|&k| k % 2 == 0);
+    /// assert_eq!(set.len(), 3);
+    /// ```
+    #[stable(feature = "retain_hash_collection", since = "1.18.0")]
+    pub fn retain<F>(&mut self, f: F)
+    where
+        F: FnMut(&T) -> bool,
+    {
+        self.base.retain(f)
+    }
+
     /// Clears the set, removing all values.
     ///
     /// # Examples
@@ -906,28 +928,6 @@ pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
     {
         self.base.take(value)
     }
-
-    /// Retains only the elements specified by the predicate.
-    ///
-    /// In other words, remove all elements `e` such that `f(&e)` returns `false`.
-    /// The elements are visited in unsorted (and unspecified) order.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::collections::HashSet;
-    ///
-    /// let mut set = HashSet::from([1, 2, 3, 4, 5, 6]);
-    /// set.retain(|&k| k % 2 == 0);
-    /// assert_eq!(set.len(), 3);
-    /// ```
-    #[stable(feature = "retain_hash_collection", since = "1.18.0")]
-    pub fn retain<F>(&mut self, f: F)
-    where
-        F: FnMut(&T) -> bool,
-    {
-        self.base.retain(f)
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]