I cannot for the life of me understand why this is not working. I am so confused. I have a class Person which has a data member age, and I just want to add two people so that it adds the ages. I don't know why this is so hard, but I'm looking for examples and I feel like everyone does something different, and for some reason NONE of them work. Sometimes the examples I see have two parameters, sometimes they only have one, sometimes the parameters are references to the object, sometimes they're not, sometimes they return an int, sometimes they return a Person object. Like..what is the most normal way to do it?

class Person {
    public: 
        int age;
        //std::string haircolor = "brown";
        //std::string ID = "23432598";

        Person(): age(19) {}

        Person operator+(Person&) { }
};

Person operator+(Person &obj1, Person &obj2){
    Person sum = obj1;
    sum += obj2;
    return sum;
}

I really feel like overloading a + operator should seriously be the easiest thing in the world except I DON'T KNOW WHAT I AM DOING. I don't know if I'm supposed to create the overload function inside the class, outside, if it makes a difference, why if I do it inside it only allows one parameter, I just honestly don't get it.