19 template<class Derived> static void once();
22 template<class Derived>
25 tonc() : onc(&grac::once<Derived>) {}
27 static Derived& get();
30 template<class Derived> void grac::once()
32 tonc<Derived>::get().h();
38 template<typename T, int = sizeof(&T::m_R)>
43 setR(T* m, has_R<T>* = 0)
46 inline void setR(...) { }