Boost smart pointers can be used with polymorphism, but how do you cast the subclass back to the pointer?
using namespace boost;
// ...
shared_ptr<SuperClass> a_ptr(new SubClass);
// ...
shared_ptr<SubClass> b_ptr = (shared_ptr<SubClass>)a_ptr; // Doesn't compile
The last line doesn't compile and gives error C2440: 'type cast' : cannot convert from 'boost::shared_ptr
<T>
' to 'boost::shared_ptr<T>
'