Cxx to Swift interop - How to access Swift enum as namespace

We frequently using Swift enum for namespace.
How such Swift enum are exposed to C++ ?
How to use it from C++ ?

Following very simple use case.

Swift side:

public enum MyNamespace { // Swift don't have namespace keyword so we uses enum.
    public class MyClass {

C++ side:

How to access ?
something like MyNamespace::MyClass::init();
doesn't work

Looks like a missing feature.