Pure Python Interfaces for *Poly types

[dave992]

If I understand correctly, the *Poly types use the Type Erasure pattern allowing developers to create their own implementations of the respective types that do not have to inherit from a common base class. The compiler can gather the used variants and create an appropriate overload for that specific combination.

I am curious how this would work with Python objects. Ideally, this wrapper should allow me to create a pure Python class that is compatible with a *Poly interface. However, I am not sure how this could work, as the compiler is not aware of any Python code at compile time. I guess you could force the compiler to create a variant with a PyObject as the templated variable, but I am not sure if that would break some of the checks or built-in functions on the C++ side.

How could the *Poly interfaces be supported on the Python side?