Why noncopyable destructor isn't virtual

[wusan@…]

Rule 14 in "Effective C++ 2/e":
   "Make sure base classes have virtual destructors."

But why base class noncopyable doesn't have ?

[nobody]

Logged In: NO 

Does anybody want to have pointers of noncopyable?

[rzymek]

Logged In: YES 
user_id=419557

This would be a problem if you used it like this:

class A : private boost::noncopyable  {
/* ... */
};

noncopyable* a = new A;
delete a;

But noncopyable isn't supposed to be used this way.

[rzymek]

Logged In: YES 
user_id=419557

This would be a problem if you used it like this:

class A : private boost::noncopyable  {
/* ... */
};

noncopyable* a = new A;
delete a;

But noncopyable isn't supposed to be used this way.

[nobody]

Logged In: NO 

one should not use the pointer to a noncopyable object

A tyical code should look something like this:

class A: private noncopyable
{
}

A* pa = new A();
delete pa;

And, the private will make sure that no one can access A
through noncopyable interface. 

So you cannot say:

noncopyable* pnc = new A();

it will create an error message like:

a.cxx: In function `int main()':
a.cxx:11: error: `noncopyable' is an inaccessible base of `A'

regards,

Sambit

[Dave Abrahams]

The answer why not is that it would add needless overhead.