feat: impl PeekingNext for std::collections::*

Author: aatifsyed

src/peeking_take_while.rs

@@ -242,11 +242,30 @@ peeking_next_by_clone! { ['a] ::std::str::Bytes<'a> }
 peeking_next_by_clone! { ['a, T] ::std::option::Iter<'a, T> }
 peeking_next_by_clone! { ['a, T] ::std::result::Iter<'a, T> }
 peeking_next_by_clone! { [T] ::std::iter::Empty<T> }
+
 #[cfg(feature = "use_alloc")]
 peeking_next_by_clone! { ['a, T] alloc::collections::linked_list::Iter<'a, T> }
 #[cfg(feature = "use_alloc")]
 peeking_next_by_clone! { ['a, T] alloc::collections::vec_deque::Iter<'a, T> }
 
+#[cfg(feature = "use_alloc")]
+peeking_next_by_clone! { ['a, K, V] alloc::collections::btree_map::Iter<'a, K, V> }
+#[cfg(feature = "use_alloc")]
+peeking_next_by_clone! { ['a, K, V] alloc::collections::btree_map::Keys<'a, K, V> }
+#[cfg(feature = "use_alloc")]
+peeking_next_by_clone! { ['a, K, V] alloc::collections::btree_map::Values<'a, K, V> }
+
+#[cfg(feature = "use_alloc")]
+peeking_next_by_clone! { ['a, T] alloc::collections::btree_set::Iter<'a, T> }
+#[cfg(feature = "use_alloc")]
+peeking_next_by_clone! { ['a, T] alloc::collections::binary_heap::Iter<'a, T> }
+
+peeking_next_by_clone! { ['a, K, V] std::collections::hash_map::Iter<'a, K, V> }
+peeking_next_by_clone! { ['a, K, V] std::collections::hash_map::Keys<'a, K, V> }
+peeking_next_by_clone! { ['a, K, V] std::collections::hash_map::Values<'a, K, V> }
+
+peeking_next_by_clone! { ['a, T] std::collections::hash_set::Iter<'a, T> }
+
 // cloning a Rev has no extra overhead; peekable and put backs are never DEI.
 peeking_next_by_clone! { [I: Clone + PeekingNext + DoubleEndedIterator]
 ::std::iter::Rev<I> }