How to write your own allocator?

  This code compiles and runs, but it doesn't print anything. I'm
completely puzzled about why. (I'm using linux gcc 4.1.2.)
  How can I write allocators which the STL containers will actually use?

#include <memory>
#include <list>
#include <iostream>

template<typename T>
class MyAlloc: public std::allocator<T>
{
 public:
    typename std::allocator<T>::pointer allocate
    (typename std::allocator<T>::size_type count,
     typename std::allocator<void>::const_pointer *hint = 0)
    {
        std::cout << "Allocation request: count = " << count
                  << ", hint = " << hint << std::endl;
        return std::allocator<T>::allocate(count, hint);
    }

    void deallocate(typename std::allocator<T>::pointer ptr,
                    typename std::allocator<T>::size_type count)
    {
        std::cout << "Deallocation request: count = " << count
                  << std::endl;
        std::allocator<T>::deallocate(ptr, count);
    }
};

int main()
{
    typedef std::list<int, MyAlloc<int> > List_t;

    List_t l;
    l.push_back(5);
    l.push_back(10);
}