The Linker is not a Magical Program

[Sclytrack]

I was wondering if the following is useful, probably not.

Reserve a spot on the vtable, which is automatically set to NULL.

class AClass
{
  __virtualspot void caption(string text);  //no implementation
  __virtualspot string caption();
}

class BClass:AClass
{
}

BClass b = new BClass();
b.caption = "test";   //compiles

1. Would compile. But it would not run if the vtable spot
   has not been filled up by some API.

2. Can derive from the class/interface, without providing
   the implementation.