Drop FnMut trait bounds from ExtractIf data structures

src/map.rs

@@ -2596,10 +2596,7 @@ impl<K, V, A: Allocator> Drain<'_, K, V, A> {
 /// assert_eq!(map.len(), 1);
 /// ```
 #[must_use = "Iterators are lazy unless consumed"]
-pub struct ExtractIf<'a, K, V, F, A: Allocator = Global>
-where
-    F: FnMut(&K, &mut V) -> bool,
-{
+pub struct ExtractIf<'a, K, V, F, A: Allocator = Global> {
     f: F,
     inner: RawExtractIf<'a, (K, V), A>,
 }

src/set.rs

@@ -1678,10 +1678,7 @@ pub struct Drain<'a, K, A: Allocator = Global> {
 /// [`extract_if`]: struct.HashSet.html#method.extract_if
 /// [`HashSet`]: struct.HashSet.html
 #[must_use = "Iterators are lazy unless consumed"]
-pub struct ExtractIf<'a, K, F, A: Allocator = Global>
-where
-    F: FnMut(&K) -> bool,
-{
+pub struct ExtractIf<'a, K, F, A: Allocator = Global> {
     f: F,
     inner: RawExtractIf<'a, (K, ()), A>,
 }

src/table.rs

@@ -2343,10 +2343,7 @@ impl<T: fmt::Debug, A: Allocator> fmt::Debug for Drain<'_, T, A> {
 /// This `struct` is created by [`HashTable::extract_if`]. See its
 /// documentation for more.
 #[must_use = "Iterators are lazy unless consumed"]
-pub struct ExtractIf<'a, T, F, A: Allocator = Global>
-where
-    F: FnMut(&mut T) -> bool,
-{
+pub struct ExtractIf<'a, T, F, A: Allocator = Global> {
     f: F,
     inner: RawExtractIf<'a, T, A>,
 }