Add missing Debug derive to vec::IntoIter

Author: zeenix

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
+- Add missing `Debug` derive to `vec::IntoIter`.
 - `bytes::BufMut` is now implemented on `VecInner`.
 - Removed generic from `history_buf::OldestOrdered`.
 - Made `LenType` opt-in.

src/vec/mod.rs

@@ -1498,6 +1498,31 @@ where
     }
 }
 
+impl<T, LenT: LenType, const N: usize> core::fmt::Debug for IntoIter<T, N, LenT>
+where
+    T: core::fmt::Debug,
+{
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let s = if self.next < self.vec.len {
+            unsafe {
+                slice::from_raw_parts(
+                    self.vec
+                        .buffer
+                        .buffer
+                        .as_ptr()
+                        .cast::<T>()
+                        .add(self.next.into_usize()),
+                    (self.vec.len - self.next).into_usize(),
+                )
+            }
+        } else {
+            &[]
+        };
+
+        write!(f, "{:?}", s)
+    }
+}
+
 impl<T, LenT: LenType, const N: usize> Drop for IntoIter<T, N, LenT> {
     fn drop(&mut self) {
         unsafe {