Why not to inherit from std::allocator

Question

I created my own allocator like so:

template
class BasicAllocator
{
    public:
        typedef size_t size_type;
        typedef ptrdiff_t         


        

Answer 1

Well, the destructor is not virtual. This is not a direct problem if you don't use the allocator polymorphically. But consider this case, where BasicAllocator inherits from std::allocator:

std::allocator* ptr = new BasicAllocator();
// ...
delete ptr;

The destructor of BasicAllocator is never called, leading to a memory leak.