class CBase {
　unsigned& (*Counter)();
public:
　CBase(unsigned& (*CountFunc)()) : Counter(CountFunc) {Counter()++;}
　~CBase() {Counter()--;}
　unsigned get_count() {return Counter();}
};

template<typename T> class CMiddle : public CBase {
　static unsigned Count;
　static unsigned& Counter() {return Count;}
public:
　CMiddle(unsigned& (*CountFunc)() = Counter) : CBase(CountFunc) {}
};
class CDerivedA: public CMiddle<CDerivedA> {};
class CDerivedB: public CMiddle<CDerivedB> {};

//-------
template<typename T> unsigned CMiddle<T>::Count;

int main()
{
　CBase *pBase;
　CDerivedA a1, a2;
　CDerivedB b1, b2, b3;
　pBase = &a1;
　cout << pBase->get_count() << endl; // 結果: 2
　pBase = &b1;
　cout << pBase->get_count() << endl; // 結果: 3
}

こういうのはだめか？>>570