C++运算符重载问题6-yiteyi-C++库

预测产量

null

                     #include<iostream>                   
                     using                               namespace                               std;                   
                     class                               A                   
                     {                   
                                         int                               i;                   
                     public                               :                   
                                         A(                               int                               ii = 0) : i(ii) {}                   
                                         void                               show() {  cout << i << endl;  }                   
                     };                   
                             
                     class                               B                   
                     {                   
                                         int                               x;                   
                     public                               :                   
                                         B(                               int                               xx) : x(xx) {}                   
                                         operator A()                               const                               {                               return                               A(x); }                   
                     };                   
                             
                     void                               g(A a)                   
                     {                   
                                         a.show();                   
                     }                   
                             
                     int                               main()                   
                     {                   
                                         B b(10);                   
                                         g(b);                   
                                         g(20);                   
                                         return                               0;                   
                     }                   