1 files changed, 96 insertions, 0 deletions
diff --git a/src/collections/hash_map.rs b/src/collections/hash_map.rs
new file mode 100644
index 0000000..b657851
--- /dev/null
+++ b/src/collections/hash_map.rs
@@ -0,0 +1,96 @@
+//! This module contains the parallel iterator types for hash maps
+//! (`HashMap<K, V>`). You will rarely need to interact with it directly
+//! unless you have need to name one of the iterator types.
+
+use std::collections::HashMap;
+use std::hash::{BuildHasher, Hash};
+use std::marker::PhantomData;
+
+use crate::iter::plumbing::*;
+use crate::iter::*;
+
+use crate::vec;
+
+/// Parallel iterator over a hash map
+#[derive(Debug)] // std doesn't Clone
+pub struct IntoIter<K: Hash + Eq + Send, V: Send> {
+    inner: vec::IntoIter<(K, V)>,
+}
+
+into_par_vec! {
+    HashMap<K, V, S> => IntoIter<K, V>,
+    impl<K: Hash + Eq + Send, V: Send, S: BuildHasher>
+}
+
+delegate_iterator! {
+    IntoIter<K, V> => (K, V),
+    impl<K: Hash + Eq + Send, V: Send>
+}
+
+/// Parallel iterator over an immutable reference to a hash map
+#[derive(Debug)]
+pub struct Iter<'a, K: Hash + Eq + Sync, V: Sync> {
+    inner: vec::IntoIter<(&'a K, &'a V)>,
+}
+
+impl<'a, K: Hash + Eq + Sync, V: Sync> Clone for Iter<'a, K, V> {
+    fn clone(&self) -> Self {
+        Iter {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+into_par_vec! {
+    &'a HashMap<K, V, S> => Iter<'a, K, V>,
+    impl<'a, K: Hash + Eq + Sync, V: Sync, S: BuildHasher>
+}
+
+delegate_iterator! {
+    Iter<'a, K, V> => (&'a K, &'a V),
+    impl<'a, K: Hash + Eq + Sync + 'a, V: Sync + 'a>
+}
+
+/// Parallel iterator over a mutable reference to a hash map
+#[derive(Debug)]
+pub struct IterMut<'a, K: Hash + Eq + Sync, V: Send> {
+    inner: vec::IntoIter<(&'a K, &'a mut V)>,
+}
+
+into_par_vec! {
+    &'a mut HashMap<K, V, S> => IterMut<'a, K, V>,
+    impl<'a, K: Hash + Eq + Sync, V: Send, S: BuildHasher>
+}
+
+delegate_iterator! {
+    IterMut<'a, K, V> => (&'a K, &'a mut V),
+    impl<'a, K: Hash + Eq + Sync + 'a, V: Send + 'a>
+}
+
+/// Draining parallel iterator that moves out of a hash map,
+/// but keeps the total capacity.
+#[derive(Debug)]
+pub struct Drain<'a, K: Hash + Eq + Send, V: Send> {
+    inner: vec::IntoIter<(K, V)>,
+    marker: PhantomData<&'a mut HashMap<K, V>>,
+}
+
+impl<'a, K: Hash + Eq + Send, V: Send, S: BuildHasher> ParallelDrainFull
+    for &'a mut HashMap<K, V, S>
+{
+    type Iter = Drain<'a, K, V>;
+    type Item = (K, V);
+
+    fn par_drain(self) -> Self::Iter {
+        let vec: Vec<_> = self.drain().collect();
+        Drain {
+            inner: vec.into_par_iter(),
+            marker: PhantomData,
+        }
+    }
+}
+
+delegate_iterator! {
+    Drain<'_, K, V> => (K, V),
+    impl<K: Hash + Eq + Send, V: Send>
+}