[boost] Re: [optional] Polymorphism

From: Philippe A. Bouchard (philippeb_at_[hidden])
Date: 2003-02-26 10:19:35

Philippe A. Bouchard wrote:

[...]

> void foo(optional<A> const &)
> {
> }
>
> int main()
> {
>     optional<B> b;
>     optional<C> c;
>
>     foo(b);
>     //foo(c);
> }

There is a bool (m_initialized) that will prevent the pointer to access
directly the virtual table.  It may not be the case if the boolean was
separated from the object, otherwise you will have 2 virtual tables and 1
boolean for one polymorphic object.  Forget the type_with_alignment benefits
in this case.

Philippe A. Bouchard