Overloading the Stream Insertion Operator

To overload the << operator for printing objects of your custom type, you need to define it as a non-member function that takes an ostream reference and a const reference to your custom type as parameters. The function should return the ostream reference to allow for chaining multiple insertions.

Here's an example of overloading the << operator for a custom Player class:

1#include <iostream>
2#include <string>
3
4class Player {
5private:
6  std::string name;
7  int score;
8
9public:
10  Player(const std::string& n, int s)
11    : name(n), score(s) {}
12
13  friend std::ostream& operator<<(
14    std::ostream& os, const Player& player) {
15    os << "Player: " << player.name
16      << ", Score: " << player.score;
17    return os;
18  }
19};
20
21int main() {
22  Player p1("Alice", 100);
23  Player p2("Bob", 200);
24
25  std::cout << p1 << "\n";
26  std::cout << p2 << "\n";
27}

1Player: Alice, Score: 100
2Player: Bob, Score: 200

In this example, we define the << operator as a non-member function that takes an ostream reference (os) and a const reference to a Player object. The function accesses the private members of the Player class, so we declare it as a friend function inside the class.

Inside the function, we use the << operator to insert the desired output format into the ostream. We return the ostream reference to allow for chaining multiple insertions.

Now we can use the << operator with Player objects just like we would with built-in types, printing them to the console or any other output stream.

By overloading the << operator, we provide a convenient way to print objects of our custom type, making the code more readable and avoiding the need for explicit printing functions.

Remember to include any necessary headers (e.g., <iostream> for std::ostream) and to adjust the output format according to your specific requirements.