C++ pimpl

[Robert Caravani]

> 
> What you're asking for is dynamic typing. You can achieve something
> equivalent using opDispatch and std.variant.

I am not sure I understood you correctly. It is dynamic typing more or less, 
just as polymorphic types like classes implement dynamic types, because you 
can change the implementation at runtime, by assigning an object of another 
derived class. 

What I am asking for is hiding the implemenation of class completely, not only 
to the programmer but also to the compiler.