Are there practical uses for dynamic-casting to void pointer?

Question

In C++, the T q = dynamic_cast(p); construction performs a runtime cast of a pointer p to some other pointer type T that must

Answer 1

Expanding on @BruceAdi's answer and inspired by this discussion, here's a polymorphic situation which may require pointer adjustment. Suppose we have this factory-type setup:

struct Base { virtual ~Base() = default; /* ... */ };
struct Derived : Base { /* ... */ };

template 
Base * Factory(Args &&... args)
{
    return ::new Derived(std::forward(args)...);
}

template 
Base * InplaceFactory(void * location, Args &&... args)
{
    return ::new (location) Derived(std::forward(args)...);
}

Now I could say:

Base * p = Factory();

But how would I clean this up manually? I need the actual memory address to call ::operator delete:

void * addr = dynamic_cast(p);

p->~Base();              // OK thanks to virtual destructor

// ::operator delete(p); // Error, wrong address!

::operator delete(addr); // OK

Or I could re-use the memory:

void * addr = dynamic_cast(p);
p->~Base();
p = InplaceFactory(addr, "some", "arguments");

delete p;  // OK now