Overloading the Subscript Operator

To overload the subscript operator [] for your custom type, you need to define a member function named operator[]. This function should take an index parameter and return a reference to the element at that index.

Here's an example of overloading the subscript operator for a custom Vector class:

1#include <iostream>
2
3class Vector {
4private:
5  float elements[3];
6
7public:
8  float& operator[](int index) {
9    return elements[index];
10  }
11
12  const float& operator[](int index) const {
13    return elements[index];
14  }
15};
16
17int main() {
18  Vector v;
19  v[0] = 1.0f;
20  v[1] = 2.0f;
21  v[2] = 3.0f;
22
23  std::cout << v[1] << "\n";
24}

12

In this example, we define two overloads of the operator[] function:

• One for non-const objects, which returns a non-const reference to the element.
• One for const objects, which returns a const reference to the element.

This allows us to use the subscript operator to access and modify elements of our Vector object, just like we would with a built-in array.