Magic methods in python are really magical. For example:

```py
class DynMember:

    def __getattr__(self, name: str):
        def fn(self, **kwargs):
            print(kwargs)

        setattr(self.__class__, name, fn)

        return lambda **x: fn(self, **x)

if __name__ == "__main__":
    d = DynMember()
    d.someFn(title="Greeting", description="Hello world!") # outputs {'title': 'Greeting', 'description': 'Hello world!'}
    d.someFn(k1="value 1", k2="value 2") # outputs {'k1': 'value 1', 'k2': 'value 2'}

```

There was no `someFn` in `DynMember` class. The method is set on the class using `__getattr__` magic method and `setattr` builtin method. These methods are really powerful and make classes do wonders in python. (have written a html generator only in 40 lines of code). How to achieve something similar in C++?