It seems that boost::any does not support polymorphism in the following sample.

class A {};

class B : public A {};

void foo( boost::any& _any )

{

try

{

A* p = any_cast< A* >( _any ); <-- Only succeed when _any contain a pointer to a object that is exactly class A, but not any object that is descendant of class A, like B.

do_some_thing( p );

}

catch( const bad_any_cast& )

{

}

void goo()

{

A* pa = new B;

boost::any a = pa;

foo( a );

}

Is it possible to make it support this polymorphism usage? Because boost::any is a type-safe replacement of void*, I hope that boost::any has the same polymorphic behavior as void*.