Update function_internal.h

Author: tadeja

cpp/src/arrow/compute/function_internal.h

@@ -352,14 +352,6 @@ static inline Result<std::shared_ptr<Scalar>> GenericToScalar(
   return MakeNullScalar(value);
 }
 
-static inline Result<std::shared_ptr<Scalar>> GenericToScalar(
-    const std::optional<std::shared_ptr<DataType>>& value) {
-  if (!value.has_value()) {
-    return std::make_shared<NullScalar>();
-  }
-  return GenericToScalar(value.value());
-}
-
 static inline Result<std::shared_ptr<Scalar>> GenericToScalar(const TypeHolder& value) {
   return GenericToScalar(value.GetSharedPtr());
 }
@@ -390,9 +382,10 @@ static inline Result<std::shared_ptr<Scalar>> GenericToScalar(std::nullopt_t) {
 }
 
 template <typename T>
-static inline auto GenericToScalar(const std::optional<T>& value)
-    -> Result<decltype(MakeScalar(value.value()))> {
-  return value.has_value() ? MakeScalar(value.value()) : std::make_shared<NullScalar>();
+static inline Result<std::shared_ptr<Scalar>> GenericToScalar(
+    const std::optional<T>& value) {
+  return value.has_value() ? GenericToScalar(value.value())
+                           : std::make_shared<NullScalar>();
 }
 
 template <typename T>