From: belopols_at_[hidden]
Date: 2001-04-11 03:43:25
Is it possible to downcast boost::shared_ptr ?
Suppose I have a container of polymorphic objects:
std::vector<boost::shared_ptr<Object> > c;
c.push_back(boost::shared_ptr<Derived>(new Derived));
I can retrieve the object and downcast it:
if (Derived* pd = dynamic_cast<Derived*>(c.front().get()))
{
pd->someMethodOfDerivedClass();
}
Now suppose that I want to call a function which expects
boost::shared_ptr<Derived>. I cannot simply create
boost::shared_ptr<Derived>(p) and pass it in, since
reference count will be wrong. What I need here is
a downcast template which I can use as follows
boost::shared_ptr<Derived> spd =
downcast<boost::shared_ptr<Derived> >(c.front());
However I don't see how to implement it using public
interface to boost::shared_ptr only.
-- Alexander Belopolsky