Не раз наталкиваюсь на токую запись

class IObject
{ 
public :
           IObject ( void ) {};
virtual ~IObject ( void ) {};
};

class TestCall :
    public IObject
    
{

private :
    int     m_i;
    float   m_f;

public :

             TestCall ( void ) { m_i = 999; m_f = 1.7777f; }
    virtual ~TestCall ( void ) {}

public :

    int __stdcall test_call_method ( int i, float f )
    {
        this->m_i = i;
        this->m_f = f;

        return m_i;
    }

};

///
int main ( int, char *[] )
{
    TestCall          test_call;
    IObject    *test_call_obj = &test_call;
    void             *v_func        = NULL;

    union
    {
        int ( __stdcall TestCall::*cFunc ) ( int, float );
        void *voidFunc;
    }; cFunc = ( &TestCall::test_call_method );
    v_func = voidFunc;


    for ( int i = 0; i < 10000; i++ )
    {
        union 
        { 
            int ( __stdcall IObject::*Method )( int, float );  
            void  *void_func; 
        }; void_func = v_func;
        int ret = ( ( test_call_obj )->* ( Method ) ) ( i, 7.999f );
        std::cout << " call method \"test_call_method\" ret = "  << ret << std::endl;
    }

    return 0;
}

Чем грозит такое приведение типов?

        union 
        { 
            int ( __stdcall IObject::*Method )( int, float );  
            void  *void_func; 
        };