A gist for a small code snippet that needs improvement

test.cpp

#include <iostream>
using namespace std;

class Test {
public:
	Test();
	int& operator[](const int& index);
	const int& operator[](const int& index) const;

private:
	int arr[10] = {};
};

Test::Test() {}


//non-constant access
int& Test::operator[](const int& index){
	cout << "Inside Non-constant Method" << endl;
	return arr[index];
}

//constant access
const int& Test::operator[](const int& index) const{
	cout << "Inside Constant Method." << endl;
	return arr[index];
}

int main() {
	Test t;
	int i = t[2];
	const int j = t[2];
	t[3] = 3;
	cout << i << endl;
	cout << j << endl;
	cout << t[3] << endl;
	return 0;
}