如何为函数参数声明自定义类型？

struct Person {
  string name;
  int age;
  string address;
};

void printPerson(Person p) {
  cout << "Name: " << p.name << endl;
  cout << "Age: " << p.age << endl;
  cout << "Address: " << p.address << endl;
}

int main() {
  Person john;
  john.name = "John Doe";
  john.age = 25;
  john.address = "123 Main St";

  printPerson(john);

  return 0;
}

class Person {
private:
  string name;
  int age;
  string address;

public:
  Person(string n, int a, string ad) {
    name = n;
    age = a;
    address = ad;
  }

  void printInfo() {
    cout << "Name: " << name << endl;
    cout << "Age: " << age << endl;
    cout << "Address: " << address << endl;
  }
};

int main() {
  Person john("John Doe", 25, "123 Main St");
  john.printInfo();

  return 0;
}