object.enable() anti-pattern

[Roy Smith]

In article <mailman.1530.1368196163.3114.python-list at python.org>,
 Oscar Benjamin <oscar.j.benjamin at gmail.com> wrote:

> It's not just because of exceptions. In C++ virtual method calls in a
> constructor for a class A will always call the methods of class A even
> if the object being constructed is actually of a subclass B because
> the B part of the object isn't initialised when the A constructor is
> called. There may be a better way to do this since I last used C++ but
> as I remember it the two-phase pattern was a recommended way to
> implement polymorphic behaviour during initialisation.

Mind.  Blown.

One of the things I love (FSVO love) about C++ is that no matter how 
much I learn, there's always whole new areas of wonderment to explore 
behind doors I didn't even know existed.

Thank you.

I suppose, if I had a class like this, I would write a factory function 
which called the constructor and post-construction initializer.  And 
then I would make the constructor protected.