Implement TryClone for Arc<T>, Option<T>, and Result<T, E> (#12615)

Author: fitzgen

crates/core/src/alloc/try_clone.rs

@@ -1,5 +1,6 @@
 use crate::error::OutOfMemory;
 use core::mem;
+use std_alloc::sync::Arc;
 
 /// A trait for values that can be cloned, but contain owned, heap-allocated
 /// values whose allocations may fail during cloning.
@@ -39,6 +40,40 @@ where
     }
 }
 
+impl<T, E> TryClone for Result<T, E>
+where
+    T: TryClone,
+    E: TryClone,
+{
+    #[inline]
+    fn try_clone(&self) -> Result<Self, OutOfMemory> {
+        match self {
+            Ok(x) => Ok(Ok(x.try_clone()?)),
+            Err(e) => Ok(Err(e.try_clone()?)),
+        }
+    }
+}
+
+impl<T> TryClone for Option<T>
+where
+    T: TryClone,
+{
+    #[inline]
+    fn try_clone(&self) -> Result<Self, OutOfMemory> {
+        match self {
+            Some(x) => Ok(Some(x.try_clone()?)),
+            None => Ok(None),
+        }
+    }
+}
+
+impl<T> TryClone for Arc<T> {
+    #[inline]
+    fn try_clone(&self) -> Result<Self, OutOfMemory> {
+        Ok(self.clone())
+    }
+}
+
 macro_rules! impl_try_clone_via_clone {
     ( $( $ty:ty ),* $(,)? ) => {
         $(