[pandas 2.0] Removing type_ and length_ members from Array base and pushing them into sub-classes and adding a signature for obtaining covariant return type for DataType #56
Removing the DataType as a member of the Array class and adding a
new virtual to Array named type_reference that makes it possible for
Array sub-classes to have a covariant return type for the DataType
Removing the length_ member from Array since is doesn't make sense
for sub-classes such as CategoryArray, since it can obtain its
length from its codes array. This changes the length function to
a virtual.
Changed the signature of Array::type to return a shared_ptr to
a const DataType instead of a non-const DataType
Add shared_ptr members to Array sub-classes that
are the expected concrete types: CategoryType, NumericType, etc.