List. How can I join them?

[shapper]

Hello,

I have two lists: List<Role> A and List<Role> B. Role is an
enumeration.

I need to update list A as follows:
- The elements in list A do not change;
- The elements that are in list B and do not exist in list A are added
to list A.

How can I do this?

Thanks,
Miguel

 

[Göran Andersson]

Hello,

I have two lists: List<Role> A and List<Role> B. Role is an
enumeration.

I need to update list A as follows:
- The elements in list A do not change;
- The elements that are in list B and do not exist in list A are added
to list A.

How can I do this?

Thanks,
Miguel

The answer is still the same as it was half an hour ago...