Vendor dependencies for 0.3.0 release

vendor/objc2-foundation/src/enumerator.rs

@@ -0,0 +1,46 @@
+//! Utilities for the `NSEnumerator` class.
+use objc2::rc::Retained;
+use objc2::Message;
+
+use super::iter;
+use crate::Foundation::NSEnumerator;
+
+// TODO: Measure whether iterating through `nextObject` or fast enumeration is
+// fastest.
+// impl<T: Message> Iterator for NSEnumerator<T> {
+//     type Item = Retained<T>;
+//
+//     #[inline]
+//     fn next(&mut self) -> Option<Retained<T>> {
+//         self.nextObject()
+//     }
+// }
+
+unsafe impl<T: Message> iter::FastEnumerationHelper for NSEnumerator<T> {
+    type Item = T;
+
+    #[inline]
+    fn maybe_len(&self) -> Option<usize> {
+        None
+    }
+}
+
+/// A consuming iterator over the items of a `NSEnumerator`.
+#[derive(Debug)]
+pub struct IntoIter<T: Message>(iter::IntoIter<NSEnumerator<T>>);
+
+__impl_iter! {
+    impl<'a, T: Message> Iterator<Item = Retained<T>> for IntoIter<T> { ... }
+}
+
+impl<T: Message> objc2::rc::RetainedIntoIterator for NSEnumerator<T> {
+    type Item = Retained<T>;
+    type IntoIter = IntoIter<T>;
+
+    #[inline]
+    fn id_into_iter(this: Retained<Self>) -> Self::IntoIter {
+        IntoIter(super::iter::IntoIter::new(this))
+    }
+}
+
+// TODO: Does fast enumeration modify the enumeration while iterating?