How to create an unordered_set of user defined class or struct in C++?

// CPP implementation to use
// user-defined data type in
// structures
#include <bits/stdc++.h>
using namespace std;

// Structure definition
struct Test {

    int id;

    // This function is used by unordered_set to compare
    // elements of Test.
    bool operator==(const Test& t) const
    {
        return (this->id == t.id);
    }
};

// class for hash function
class MyHashFunction {
public:
    // id is returned as hash function
    size_t operator()(const Test& t) const
    {
        return t.id;
    }
};

// Driver method
int main()
{
    // put values in each
    // structure define below.
    Test t1 = { 110 }, t2 = { 102 },
         t3 = { 101 }, t4 = { 115 };

    // define a unordered_set having
    // structure as its elements.
    unordered_set<Test, MyHashFunction> us;

    // insert structure in unordered_set
    us.insert(t1);
    us.insert(t2);
    us.insert(t3);
    us.insert(t4);

    // printing the elements of unordered_set
    for (auto e : us) {
        cout << e.id << " ";
    }

    return 0;
}

// CPP program to demonstrate working of unordered_set
// for user defined data types.
#include <bits/stdc++.h>
using namespace std;

struct Person {
    string first, last;

    Person(string f, string l)
    {
        first = f;
        last = l;
    }

    bool operator==(const Person& p) const
    {
        return first == p.first && last == p.last;
    }
};

class MyHashFunction {
public:

    // We use predefined hash functions of strings
    // and define our hash function as XOR of the
    // hash values.
    size_t operator()(const Person& p) const
    {
        return (hash<string>()(p.first)) ^ (hash<string>()(p.last));
    }
};

// Driver code
int main()
{
    unordered_set<Person, MyHashFunction> us;
    Person p1("kartik", "kapoor");
    Person p2("Ram", "Singh");
    Person p3("Laxman", "Prasad");

    us.insert(p1);
    us.insert(p2);
    us.insert(p3);

    for (auto e : us) {
        cout << "[" << e.first << ", "
             << e.last << "]\n";
    }

    return 0;
}