[Boost-users] shared_ptr implicit dynamic cast

12 Jul 2006

      hello

given the following class hierarchy

    class Foo {
    protected:
        virtual ~Foo() {}
    };

    class Bar : public Foo {};

and declaration

    boost::shared_ptr<Foo> foo;

is there any difference between the two assignment statements below?

    foo = boost::shared_ptr<Foo>(new Bar);
    foo = boost::shared_ptr<Bar>(new Bar);

in other words, when you assign a value to a shared_ptr, does it make
any difference what class you specify for that value, as long as the
class of the underlying object can be dynamically cast to the class
that was used to declare the shared_ptr?

kind regards,
eric