分析一下这段程序的输出(Autodesk)class B{public:B(){cout$amp;<amp;<quot;$default constructor"&lclass B { public: B() { cout$amp;} ~B() { cout$amp;} B(int i):data(i) //B(int) works as a converter (int -> instance of B) { cout$amp;} private: int data; }; B Play(B b) { return b ; }