I am having problem with the << operator in the owner file - c++

Question

I have made a programme that has two types of classes that implements owner as well as dogs , I am having a problem with the iterator part in the << operator in the Owner.h file, I know that we can't use an iterator for an STL container having its type as a custom class , but then what is the alternative to do so ?
I am attaching the files for you reference with the main file
I know this is a lot to ask from you guys , but just recommend me a way and i'll figure it out
Thanks
Main File
#include <iostream>
#include "Owner.h"
#include "Dog.h"
using namespace std;
void Purchase(Owner& owner, Dog& dog) {
owner.AddDog(dog);
dog.SetOwner(owner);
}
int main() {
Owner owner1("Michael Hagley", "14 Brentwood Terrace");
Owner owner2("Oliver Walter", "299 Mill Road");
Dog dog1("Cheeto", 5, 2000.00);
Dog dog2("Mavrick", 8, 1800.00);
Dog dog3("Biglet", 4, 2100.00);
Dog dog4("Snoopy", 11, 600.00);
Dog dog5("Leggo", 2, 500.00);
Dog dog6("Bugsy", 4, 1100.00);
Purchase(owner1, dog1);
Purchase(owner1, dog5);
Purchase(owner2, dog2);
Purchase(owner2, dog3);
Purchase(owner2, dog6);
cout<<owner1.GetName()<<" Has the following dogs"<<std::endl;
cout<<std::endl;
cout<<owner2.GetName()<<"has the following dogs"<<std::endl;
// cout << owner1;
//
// cout << owner2;
Owner* owner = dog1.GetOwner();
if (owner) cout << dog1.GetName() << " belongs to " << owner->GetName() << endl;
owner = dog4.GetOwner();
if (owner){
cout << dog4.GetName() << " belongs to " << owner->GetName() << endl;
}
else{
cout<<dog4.GetName()<<" Has no owner"<<endl;
}
return 0;
}
Owner File
//
// Created by Kannav Sethi on 21/04/22.
//
#ifndef FINALS_OWNER_H
#define FINALS_OWNER_H
#include <iostream>
#include <vector>
//Wwe'll be using the concept of association and aggregation here
class Dog;
class Owner{
// provided the variables for the Owner here
// the only viable STL container here is vectors of type dogs
//but there is a problem with it , I wont be able to iterate over the dogs vector due to it being of a custom type
//Lets try that out here
std::string name;
std::string address;
std::vector<Dog> dogs;
int size=0;
public:
// constructor
Owner(){
name="";
address="";
};
//constructor
Owner(std::string name,std::string address){
this->name=name;
this->address=address;
};
// tried out making a copy assignment but it was futile
// Owner& operator=(Owner& oTemp){
// this->name=oTemp.name;
// this->address=oTemp.address;
// for(auto i = oTemp.dogs.begin();i!=oTemp.dogs.end();i++){
// this->dogs.push_back(i);
// }
// return *this;
// }
//add dog
void AddDog(Dog& dog){
dogs.push_back(dog);
size++;
}
//get name function
std::string GetName(){
return this->name;
}
friend std::ostream& operator<<(std::ostream& os,Owner& owner);
};
std::ostream& operator<<(std::ostream& os,Owner& owner){
std::vector<Dog>::iterator it;
os<<owner.name<<"of "<<owner.address<<" has the following dogs"<<std::endl;
double sum=0;
for(auto it=owner.dogs.begin();it!=owner.dogs.end();it){
it.operator++();
sum+=it.cost;
}
std::cout<<"the total costs of all the dogs are $"<<sum<<std::endl;
#endif //FINALS_OWNER_H
Dog file
//
// Created by Kannav Sethi on 21/04/22.
//
#ifndef FINALS_DOG_H
#define FINALS_DOG_H
#include <iostream>
#include "Owner.h"
class Owner;
class Dog{
// the variables
std::string name;
int age;
double cost;
Owner* owner;
public:
// constructors
Dog(std::string name,int age,double cost){
this->name=name;
this->age=age;
this->cost=cost;
}
// set owner
void SetOwner(Owner& _owner){
this->owner=(&_owner);
}
// get owner
Owner* GetOwner(){
return this->owner;
}
// getName
std::string GetName(){
return this->name;
}
// this streaming operator works but not the one I used in Owner
friend std::ostream& operator<<(std::ostream& os, Dog dog);
};
std::ostream& operator<<(std::ostream& os, Dog dog){
os<<dog.name<<" is "<<dog.age<<" years old and costs "<<dog.cost<<std::endl;
}
#endif //FINALS_DOG_H

Answer 1

You need
std::ostream& operator<<(std::ostream& os, Owner& owner) {
os << owner.name << "of " << owner.address << " has the following dogs" << std::endl;
double sum = 0;
for (auto it = owner.dogs.begin(); it != owner.dogs.end(); it++) {
sum += it->cost;
std::cout << it->name << std::endl;
}
std::cout << "the total costs of all the dogs are $" << sum << std::endl;
return os;
}
You didnt seem to realize that you have to use '->' with an iterator
You also need to make this a friend of Dog (cost is private)
// this streaming operator works but not the one I used in Owner
friend std::ostream& operator<<(std::ostream& os, Dog dog);
friend std::ostream& operator<<(std::ostream& os, Owner& o);