1 files changed, 17 insertions, 2 deletions
diff --git a/library/core/src/iter/adapters/copied.rs b/library/core/src/iter/adapters/copied.rs
index 62d3afb81..8f6b2904e 100644
--- a/library/core/src/iter/adapters/copied.rs
+++ b/library/core/src/iter/adapters/copied.rs
@@ -4,6 +4,7 @@ use crate::iter::adapters::{
 use crate::iter::{FusedIterator, TrustedLen};
 use crate::mem::MaybeUninit;
 use crate::mem::SizedTypeProperties;
+use crate::num::NonZeroUsize;
 use crate::ops::Try;
 use crate::{array, ptr};
 
@@ -89,7 +90,7 @@ where
     }
 
     #[inline]
-    fn advance_by(&mut self, n: usize) -> Result<(), usize> {
+    fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
         self.it.advance_by(n)
     }
 
@@ -130,7 +131,7 @@ where
     }
 
     #[inline]
-    fn advance_back_by(&mut self, n: usize) -> Result<(), usize> {
+    fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
         self.it.advance_back_by(n)
     }
 }
@@ -240,3 +241,17 @@ where
         }
     }
 }
+
+#[stable(feature = "default_iters", since = "1.70.0")]
+impl<I: Default> Default for Copied<I> {
+    /// Creates a `Copied` iterator from the default value of `I`
+    /// ```
+    /// # use core::slice;
+    /// # use core::iter::Copied;
+    /// let iter: Copied<slice::Iter<'_, u8>> = Default::default();
+    /// assert_eq!(iter.len(), 0);
+    /// ```
+    fn default() -> Self {
+        Self::new(Default::default())
+    }
+}