[PATCH v2 1/2] rust: sync: impl {Debug,Display} for {Unique,}Arc

[Boqun Feng <boqun.feng@gmail.com>]

This allows printing the inner data of `Arc` and its friends if the
inner data implements `Display` or `Debug`. It's useful for logging and
debugging purpose.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviwed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
---
 rust/kernel/sync/arc.rs | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 519a6ec43644..e6176d9b5b29 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -22,6 +22,7 @@ use crate::{
 };
 use alloc::boxed::Box;
 use core::{
+    fmt,
     marker::{PhantomData, Unsize},
     mem::{ManuallyDrop, MaybeUninit},
     ops::{Deref, DerefMut},
@@ -522,3 +523,27 @@ impl<T: ?Sized> DerefMut for UniqueArc<T> {
         unsafe { &mut self.inner.ptr.as_mut().data }
     }
 }
+
+impl<T: fmt::Display + ?Sized> fmt::Display for UniqueArc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.deref(), f)
+    }
+}
+
+impl<T: fmt::Display + ?Sized> fmt::Display for Arc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.deref(), f)
+    }
+}
+
+impl<T: fmt::Debug + ?Sized> fmt::Debug for UniqueArc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self.deref(), f)
+    }
+}
+
+impl<T: fmt::Debug + ?Sized> fmt::Debug for Arc<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self.deref(), f)
+    }
+}
-- 
2.39.1