Implement Debug for Padding

src/types.rs

@@ -6,6 +6,9 @@ use crate::prelude::*;
 
 /// A transparent wrapper over `MaybeUninit<T>` to represent uninitialized padding
 /// while providing `Default`.
+// This is restricted to `Copy` types since that's a loose indicator that zeros is actually
+// a valid bitpattern. There is no technical reason this is required, though, so it could be
+// lifted in the future if it becomes a problem.
 #[allow(unused)]
 #[repr(transparent)]
 #[derive(Clone, Copy)]
@@ -17,6 +20,16 @@ impl<T: Copy> Default for Padding<T> {
     }
 }
 
+impl<T: Copy> fmt::Debug for Padding<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Taken frmo `MaybeUninit`'s debug implementation
+        // NB: there is no `.pad_fmt` so we can't use a simpler `format_args!("Padding<{..}>").
+        let full_name = core::any::type_name::<Self>();
+        let prefix_len = full_name.find("Padding").unwrap();
+        f.pad(&full_name[prefix_len..])
+    }
+}
+
 /// The default repr type used for C style enums in Rust.
 #[cfg(target_env = "msvc")]
 #[allow(unused)]