Using boost function with boost bind with a map

Question

In this code, the line (iter->second)(); calls the function reset(new childClass()). Is this correct ? If this is the case, it is called on whi

Answer 1

the line (iter->second)(); calls the function reset(new childClass()). Is this correct?

No, it invokes reset(). If you want it to be called as reset(new childClass()), you need to pass new childClass() to boost::bind as argument like

boost::bind( static_cast<void( boost::shared_ptr<BaseClass>::* )(BaseClass*)>( 
               &boost::shared_ptr<BaseClass>::reset ), 
             boost::shared_ptr<BaseClass>(new childClass() ),
             new childClass() )

Note that new childClass() itself is evaluated when boost::bind is invoked, not the functor is invoked.

Or you can add a placeholder, and pass new childClass() when call the functor.

it is called on which object ?

It's called on the object copied from the argument passed to boost::bind, i.e. boost::shared_ptr<BaseClass>(new childClass() ).