C/code/船和卡车的重量计算——友元函数——11-02.cpp

#include <iostream>
using namespace std;

class car;

class boat {
private:
    int weight;
public:
    boat(int w) : weight(w) {}
    friend int totalweight(const boat& b, const car& c);
    void display() const {
        cout << "boat's weight:" << weight << endl;
    }
    ~boat() {
        cout << "boat is destruction" << endl;
    }
};

class car {
private:
    int weight;
public:
    car(int w) : weight(w) {}
    friend int totalweight(const boat& b, const car& c);
    void display() const {
        cout << "car's weight:" << weight << endl;
    }
    ~car() {
        cout << "car is destruction" << endl;
    }
};

int totalweight(const boat& b, const car& c) {
    b.display();
    c.display();
    cout << "total weight:" << b.weight + c.weight << endl;
    return b.weight + c.weight;
}

int main() {
    int boat_weight, car_weight;
    cin >> boat_weight >> car_weight;

    boat b(boat_weight);
    car c(car_weight);

    totalweight(b, c);

    return 0;
}