In C++ a stack-allocated object can be declared const:
const Class object;
after that trying to call a non-const method on suc
In your heap example, new returns a pointer to non-const. The fact that you've stored it in a pointer to const (and then const_casted it back to a pointer to non-const) doesn't change the fact that the object itself is not const in the same way as the stack-allocated one is.
However, you can create a const object on the heap:
const Class* object = new const Class();
In such a case, casting to a pointer to non-const and calling a non-const method would be the same situation as the const stack-allocated object.
(The idea of creating a const object on the heap was new to me, I had never seen that before. Thanks to Charles Bailey.)