Changes because MSVC tries to instantiate NumericScalar for Time/Timestamp types

Change-Id: I00ca69a9c1ec1ddaa5b1fd9db35e9db09a12eb8b

Author: wesm

cpp/src/arrow/scalar.cc

@@ -32,19 +32,19 @@ using internal::checked_cast;
 
 Time32Scalar::Time32Scalar(int32_t value, const std::shared_ptr<DataType>& type,
                            bool is_valid)
-    : NumericScalar(value, type, is_valid) {
+    : Scalar{type, is_valid}, value(value) {
   DCHECK_EQ(Type::TIME32, type->id());
 }
 
 Time64Scalar::Time64Scalar(int64_t value, const std::shared_ptr<DataType>& type,
                            bool is_valid)
-    : NumericScalar(value, type, is_valid) {
+    : Scalar{type, is_valid}, value(value) {
   DCHECK_EQ(Type::TIME64, type->id());
 }
 
 TimestampScalar::TimestampScalar(int64_t value, const std::shared_ptr<DataType>& type,
                                  bool is_valid)
-    : NumericScalar(value, type, is_valid) {
+    : Scalar{type, is_valid}, value(value) {
   DCHECK_EQ(Type::TIMESTAMP, type->id());
 }
 

cpp/src/arrow/scalar.h

@@ -109,20 +109,23 @@ class ARROW_EXPORT Date64Scalar : public NumericScalar<Date64Type> {
   using NumericScalar<Date64Type>::NumericScalar;
 };
 
-class ARROW_EXPORT Time32Scalar : public NumericScalar<Time32Type> {
+class ARROW_EXPORT Time32Scalar : public Scalar {
  public:
+  int32_t value;
   Time32Scalar(int32_t value, const std::shared_ptr<DataType>& type,
                bool is_valid = true);
 };
 
-class ARROW_EXPORT Time64Scalar : public NumericScalar<Time64Type> {
+class ARROW_EXPORT Time64Scalar : public Scalar {
  public:
+  int64_t value;
   Time64Scalar(int64_t value, const std::shared_ptr<DataType>& type,
                bool is_valid = true);
 };
 
-class ARROW_EXPORT TimestampScalar : public NumericScalar<TimestampType> {
+class ARROW_EXPORT TimestampScalar : public Scalar {
  public:
+  int64_t value;
   TimestampScalar(int64_t value, const std::shared_ptr<DataType>& type,
                   bool is_valid = true);
 };