Re: [Boost-users] shared_from_this - derived classes (yes, I googled)

Well, I tried to get a trivial example and ended up having a working example. I suppose my problem is in the non-trivial part of my code :)

Is this the correct way to do it?

#include <iostream>

#include #include

//-------------------------- class A : public boost::enable_shared_from_this<A> { public:

   ///    typedef boost::shared_ptr<A> SmartPtr;

   ///    static A::SmartPtr Create()    {        A::SmartPtr instance;

       // Check arguments if any

       // Create an instance of this class        instance.reset(new A());

       return instance;    }

   virtual ~A()    {    }

protected:

   A()    {    }

};

//-------------------------- class B : public A { public:

   ///    typedef boost::shared_ptr<B> SmartPtr;

   ///    static B::SmartPtr Create()    {        B::SmartPtr instance;

       // Check arguments if any

       // Create an instance of this class        instance.reset(new B());

       return instance;    }

   ///    virtual ~B()    {    }

   ///    B::SmartPtr Foo()    {        A::SmartPtr temp = shared_from_this();        B::SmartPtr me   = boost::shared_dynamic_cast(temp);

       return me;    }

   ///    void Bar() const    {        std::cout << "Success!" << std::endl;    }

protected:

   ///    B()        :        A()    {    } };

//-------------------------- int main() {    B::SmartPtr b1 = B::Create();    B::SmartPtr b2 = b1->Foo();

   if( b1 != b2 )    {        std::cout << "they aren't equal." << std::endl;        return 1;    }

   b2->Bar();

   return 0; }

Your example compiles and works well. (Actually, you don't need shared_dynamic_cast here, static_pointer_cast would be well enough.)