class D { int a,b; public: D(int i = 0, int j=0):a(i),b(j){ } D(D&p){a = p.a;b=p.a;} void show(){cout<<a<<""<<b<<endl; } }; D f(D p){ D d1(p); return d1; } int main() { D o1,o2(2,3);//?? o2 = f(o1); o2.show(); return 0; }