#include<iostream>#include<algorithm>#include<iomanip>#include<cmath>#include<string.h>#include<stdlib.h>#include<sstream>using namespace std;class two;class one{private :?string name;public :?void show(two &);?void setOne(){??string? s;??name = s;?}};class two{private :?string name;public :?friend void one::show(two &);?void setTwo(){??string? s;??name = s;?}};void one :: show(two &s){?cout << s.name << endl;?? //編譯器報錯，無法訪問name，這是為什么？}int main(){?one a;?two b;?a.setOne();?a.show(b);?b.setTwo();?return 0;}