c++ 指向另一个类错误的指针 "no operator matches these operands."

Question

编辑* 我很笨...感谢您帮助我解决了这个问题。*在我的 car 类中，下面的代码不断给我一个关于 << operators

的错误

cout << "Driver: " << driver->print(); 
cout << "Owner: " << owner->print();

错误显示“没有运算符匹配这些操作数。”这是我的家庭作业，所以我确实需要以某种方式从驱动程序调用打印功能。在主要功能中，我实际上还没有设置驱动程序或所有者，但我认为这无关紧要。提前致谢。

#include <iostream>
#include <string>
#include <vector>

using namespace std;

class Person
{
public:
Person(string _name,int _age)
{
    _name = name;
    _age = age;
    cout << "Name: " << name << endl;
    cout << "Age: " << age << endl;
}
string getName()
{
    return name;
}
int getAge()
{
    return age;
}
int incrementAge()
{
    age +=1;
    return age;
}
void print()
{
    cout << "Name: " << name << endl;
    cout << "Age: " << age << endl;

}


private:
string name;
int age;

};

class Car
{
public:
Car (string m)
{
    model = m;
}
void setDriver(Person *d)
{
    *driver = *d;
}
void setOwner(Person *o)
{
    *owner = *o;
}
void print()
{
    cout << "Model: " << model << endl;
    cout << "Driver: " << driver->print();
    cout << "Owner: " << owner->print();
}




private:

string model;
Person *owner;
Person *driver;


};

int main()
{
vector<Person*>people;
vector<Car*>cars;
string name = "";
int age = 0;
string model = 0;
int sentValue = 0;
while (sentValue != -1)
{
    cout << "Enter name: ";
    cin >> name;
    cout << "Enter age: ";
    cin >> age;


    people.push_back(new Person(name, age));
    cout << "Enter car model: ";
    cin >> model;
            cars.push_back(new Car(model));
    cout << "Press -1 to stop, or 1 to enter info for others: ";
    cin >> sentValue;
}






//display car model, 
//owner’s name and age,
//and driver’s name and age.

system("pause");
return 0;
   }

Answer 1

执行此操作的 C++ 方法是实现 std::ostream&<< Person 的运算符和 Car .例如，

#include <iostream>

std::ostream& operator<<(std::ostream& o, const Person& p) {
  return o << "Name: " << p.getName() << " Age: " << p.getAge();
}

然后像这样使用:

Person p("Bob", 23);
std::cout << p << "\n";

顺便说一句，我认为您的代码中并不真的需要所有这些指针。