How can polymorphism be achieved in data-oriented design without the use of OO? [closed]

I'm trying to bridge the gap between the OO and FP paradigms, and I'm looking into data-oriented design. I've found that there aren't many agreed-upon best practices or architectural patterns that I can just lift from.

One common problem in the C++ domain is trying to do polymorphic extension. This can be done very easily in OO using virtual methods and inheritance.

What would be a suitable, equivalent pattern to use in the data-oriented design paradigm?