Re: [Boost-users] polymorphism and boost::shared_ptr

From: Michael Fawcett (michael.fawcett_at_[hidden])
Date: 2007-09-07 18:16:15

On 9/7/07, Brad Ryder <bradryder67_at_[hidden]> wrote:
> Hi Michael,
>
> Thanks for the response.  Your solution will indeed work, but the side
> effect is that spB and spC only have access to methods available in
> the base class.  Imagine that B & C have unique methods that I want to
> access in main like.
>
> main()
> {
>
> A base;
> shPtrB spB(new B());
> shPtrC spC(new C());
>
> spB.PrintBrad();        // unique to B
> spC.PrintMichael();   // unique to C
>
> // this will fail obviously, but how else can I get access to unique
> methods in B & C
> base.AddChild(spB);
> base.AddChild(spC);
> }
>
> Thanks for your help

Try to remember not to top-post.

Generally you should not need to know if the instances are indeed A,
B, or C.  If you did, why would you be storing them in a container of
base class pointers?

If you find you really need to perform the cast, look at
boost::static_pointer_cast.

--Michael Fawcett