1 files changed, 86 insertions, 0 deletions
diff --git a/third_party/rust/cranelift-entity-0.41.0/src/iter.rs b/third_party/rust/cranelift-entity-0.41.0/src/iter.rs
new file mode 100644
index 0000000000..8c681023d2
--- /dev/null
+++ b/third_party/rust/cranelift-entity-0.41.0/src/iter.rs
@@ -0,0 +1,86 @@
+//! A double-ended iterator over entity references and entities.
+
+use crate::EntityRef;
+use core::iter::Enumerate;
+use core::marker::PhantomData;
+use core::slice;
+
+/// Iterate over all keys in order.
+pub struct Iter<'a, K: EntityRef, V>
+where
+    V: 'a,
+{
+    enumerate: Enumerate<slice::Iter<'a, V>>,
+    unused: PhantomData<K>,
+}
+
+impl<'a, K: EntityRef, V> Iter<'a, K, V> {
+    /// Create an `Iter` iterator that visits the `PrimaryMap` keys and values
+    /// of `iter`.
+    pub fn new(iter: slice::Iter<'a, V>) -> Self {
+        Self {
+            enumerate: iter.enumerate(),
+            unused: PhantomData,
+        }
+    }
+}
+
+impl<'a, K: EntityRef, V> Iterator for Iter<'a, K, V> {
+    type Item = (K, &'a V);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.enumerate.next().map(|(i, v)| (K::new(i), v))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.enumerate.size_hint()
+    }
+}
+
+impl<'a, K: EntityRef, V> DoubleEndedIterator for Iter<'a, K, V> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.enumerate.next_back().map(|(i, v)| (K::new(i), v))
+    }
+}
+
+impl<'a, K: EntityRef, V> ExactSizeIterator for Iter<'a, K, V> {}
+
+/// Iterate over all keys in order.
+pub struct IterMut<'a, K: EntityRef, V>
+where
+    V: 'a,
+{
+    enumerate: Enumerate<slice::IterMut<'a, V>>,
+    unused: PhantomData<K>,
+}
+
+impl<'a, K: EntityRef, V> IterMut<'a, K, V> {
+    /// Create an `IterMut` iterator that visits the `PrimaryMap` keys and values
+    /// of `iter`.
+    pub fn new(iter: slice::IterMut<'a, V>) -> Self {
+        Self {
+            enumerate: iter.enumerate(),
+            unused: PhantomData,
+        }
+    }
+}
+
+impl<'a, K: EntityRef, V> Iterator for IterMut<'a, K, V> {
+    type Item = (K, &'a mut V);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.enumerate.next().map(|(i, v)| (K::new(i), v))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.enumerate.size_hint()
+    }
+}
+
+impl<'a, K: EntityRef, V> DoubleEndedIterator for IterMut<'a, K, V> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.enumerate.next_back().map(|(i, v)| (K::new(i), v))
+    }
+}
+
+impl<'a, K: EntityRef, V> ExactSizeIterator for IterMut<'a, K, V> {}