Are type fields pure evil?

Question

As discusses in The c++ Programming Language 3rd Edition in section 12.2.5, type fields tend to create code that is less versatile, error-prone, less intuitive, and less maintai

Answer 1

The following guideline is from Clean Code by Robert C. Martin. "My general rule for switch statements is that they can be tolerated if they appear only once, are used to create polymorphic objects, and are hidden behind an inheritance relationship so that the rest of the system can't see them".

The rationale is this: if you expose type fields to the rest of your code, you'll get multiple instances of the above switch statement. That is a clear violation of DRY. When you add a type, all these switches need to change (or, even worse, they become inconsistent without breaking your build).