     1	class B : public A
     2	{
     3		.....
     4	private:
     5		bool constructed
     6	};
     7	
     8	B::B(DeviceClass *cl,const char *s):A(cl,s),constructed(false)
     9	{
    10		....
    11		init_device();
    12		constructed = true;
    13	}
    14	
    15	void T::init_device()
    16	{
    17		if (constructed == true)
    18		 	A::init_device();
    19	
    20		....
    21	}
