fork download

copy

#include <cstdlib>
#include <iostream> 
#include <cstring>  
using namespace std;
 
class person {
string name;
public:
 
    person(const string &n){
        name=n;
    }   
    virtual person& print(const person&){}   
};
 
class worker:public person {
    int number;
public:
    worker(const string &n , int num ):person(n){
        number=num;
    }
 
    virtual worker& print(const worker& x){
        cout << number << x.number<< endl; 
        return number+=number;
    }
};
 
int main(int argc, char** argv) {
 
    person *p = new worker("john",1);
    person *g = new worker("jack",2);
    worker c = p->print(*g);
 
    return 0;
}

prog.cpp: In member function ‘virtual person& person::print(const person&)’:
prog.cpp:13:42: warning: no return statement in function returning non-void [-Wreturn-type]
     virtual person& print(const person&){}   
                                          ^
prog.cpp: In member function ‘virtual worker& worker::print(const worker&)’:
prog.cpp:25:24: error: invalid initialization of reference of type ‘worker&’ from expression of type ‘int’
         return number+=number;
                        ^
prog.cpp: In function ‘int main(int, char**)’:
prog.cpp:33:27: error: conversion from ‘person’ to non-scalar type ‘worker’ requested
     worker c = p->print(*g);
                           ^
prog.cpp: In member function ‘virtual worker& worker::print(const worker&)’:
prog.cpp:26:5: warning: control reaches end of non-void function [-Wreturn-type]
     }
     ^

Standard output is empty