Derive Copy for TimeUnit and IntervalUnit (apache#5840)

* Derive `Copy` for `TimeUnit` and `IntervalUnit`

* Fix clippy warnings

* Rustfmt

Author: mbrobbel

arrow-cast/src/cast/mod.rs

@@ -1660,7 +1660,7 @@ pub fn cast_with_options(
             let array = cast_with_options(array, &Int64, cast_options)?;
             Ok(make_timestamp_array(
                 array.as_primitive(),
-                unit.clone(),
+                *unit,
                 tz.clone(),
             ))
         }
@@ -1721,11 +1721,7 @@ pub fn cast_with_options(
                 }
                 _ => converted,
             };
-            Ok(make_timestamp_array(
-                &adjusted,
-                to_unit.clone(),
-                to_tz.clone(),
-            ))
+            Ok(make_timestamp_array(&adjusted, *to_unit, to_tz.clone()))
         }
         (Timestamp(TimeUnit::Microsecond, _), Date32) => {
             timestamp_to_date32(array.as_primitive::<TimestampMicrosecondType>())
@@ -4020,7 +4016,7 @@ mod tests {
                 TimeUnit::Microsecond,
                 TimeUnit::Nanosecond,
             ] {
-                let to_type = DataType::Timestamp(time_unit.clone(), None);
+                let to_type = DataType::Timestamp(*time_unit, None);
                 let b = cast(array, &to_type).unwrap();
 
                 match time_unit {

arrow-schema/src/datatype.rs

@@ -327,7 +327,7 @@ pub enum DataType {
 }
 
 /// An absolute length of time in seconds, milliseconds, microseconds or nanoseconds.
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum TimeUnit {
     /// Time in seconds.
@@ -341,7 +341,7 @@ pub enum TimeUnit {
 }
 
 /// YEAR_MONTH, DAY_TIME, MONTH_DAY_NANO interval in SQL style.
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum IntervalUnit {
     /// Indicates the number of elapsed whole months, stored as 4-byte integers.