Add try_downcast_array helper

Author: emilk

crates/utils/re_arrow_util/src/arrays.rs

@@ -20,6 +20,10 @@ pub trait ArrowArrayDowncastRef<'a>: 'a {
     /// Similar to `downcast_array_ref`, but returns an error in case the downcast
     /// returns `None`.
     fn try_downcast_array_ref<T: Array + 'static>(self) -> Result<&'a T, ArrowError>;
+
+    /// Similar to `downcast_array_ref`, but returns an error in case the downcast
+    /// returns `None`.
+    fn try_downcast_array<T: Array + Clone + 'static>(self) -> Result<T, ArrowError>;
 }
 
 impl<'a> ArrowArrayDowncastRef<'a> for &'a dyn Array {
@@ -36,6 +40,12 @@ impl<'a> ArrowArrayDowncastRef<'a> for &'a dyn Array {
             ))
         })
     }
+
+    /// Similar to `downcast_array_ref`, but returns an error in case the downcast
+    /// returns `None`.
+    fn try_downcast_array<T: Array + Clone + 'static>(self) -> Result<T, ArrowError> {
+        Ok(self.try_downcast_array_ref::<T>()?.clone())
+    }
 }
 
 impl<'a> ArrowArrayDowncastRef<'a> for &'a ArrayRef {
@@ -52,6 +62,12 @@ impl<'a> ArrowArrayDowncastRef<'a> for &'a ArrayRef {
             ))
         })
     }
+
+    /// Similar to `downcast_array_ref`, but returns an error in case the downcast
+    /// returns `None`.
+    fn try_downcast_array<T: Array + Clone + 'static>(self) -> Result<T, ArrowError> {
+        Ok(self.try_downcast_array_ref::<T>()?.clone())
+    }
 }
 
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