Implement Default for some alloc/core iterators

This way one can `mem::take()` them out of structs or #[derive(Default)] on structs containing them.

These changes will be insta-stable.

1 files changed, 7 insertions, 0 deletions

diff --git a/library/alloc/src/collections/binary_heap/mod.rs b/library/alloc/src/collections/binary_heap/mod.rs
index f1d0a305d99..b0ec70ad565 100644
--- a/library/alloc/src/collections/binary_heap/mod.rs
+++ b/library/alloc/src/collections/binary_heap/mod.rs
@@ -1468,6 +1468,13 @@ impl<T> ExactSizeIterator for IntoIter<T> {
 #[stable(feature = "fused", since = "1.26.0")]
 impl<T> FusedIterator for IntoIter<T> {}
 
+#[stable(feature = "default_iters", since = "CURRENT_RUSTC_VERSION")]
+impl<T> Default for IntoIter<T> {
+    fn default() -> Self {
+        IntoIter { iter: Default::default() }
+    }
+}
+
 // In addition to the SAFETY invariants of the following three unsafe traits
 // also refer to the vec::in_place_collect module documentation to get an overview
 #[unstable(issue = "none", feature = "inplace_iteration")]