Is this code standard compliant or not?

So the code is

class A
{
public:
   int i;
   A(){
       i = 5;
   }
};
class B : public A
{
public:
   void someFunc();
};

class C
{
   A myObj;
public:
   void func(){
       B* foo = reinterpret_cast<B*>(&myObj);
       foo->someFunc();
   }
};

Assuming that classes will stay as they are and never change, is this use of reinterpret_cast correct(i think that it's not)? If not, which exact parts of C++ standard(you can use any edition) are violated here?