Use-after-free in C++

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

class A
{
public:
	virtual void func();
};

class B : public A
{
public:
	virtual void func() override;
};

void A::func()
{
	printf("Hello world\n");
}

void B::func()
{
	printf("How did I get here?\n");
}


int main()
{
	A *a = new A();

	a->func();

	delete a; // use-after-free... free here, and use 'a' again later on

	B *b = new B();

	b->func(); // test our function, it should be the new one.

	a->func(); // now use-after-free -- this should be the same new function.

	// As you can see, you don't even need a write primitive, since (in this case) it automatically
	// changes the vtable (virtual function pointer) for you.
	
}