Memory Leak Prevention in C++

1#include <iostream>
2using namespace std;
3
4class Resource {
5private:
6    int* data;
7    int size;
8
9public:
10    Resource(int s) {
11        size = s;
12        data = new int[size];
13        cout << "Resource allocated: " << size << " integers" << endl;
14    }
15    
16    // Destructor - prevents memory leak
17    ~Resource() {
18        if (data != nullptr) {
19            delete[] data;
20            data = nullptr;
21            cout << "Resource freed" << endl;
22        }
23    }
24    
25    // Copy constructor - deep copy
26    Resource(const Resource& other) {
27        size = other.size;
28        data = new int[size];
29        for (int i = 0; i < size; i++) {
30            data[i] = other.data[i];
31        }
32        cout << "Resource copied (deep copy)" << endl;
33    }
34    
35    // Assignment operator - prevent double deletion
36    Resource& operator=(const Resource& other) {
37        if (this != &other) {  // Self-assignment check
38            delete[] data;  // Free existing memory
39            
40            size = other.size;
41            data = new int[size];
42            for (int i = 0; i < size; i++) {
43                data[i] = other.data[i];
44            }
45        }
46        return *this;
47    }
48    
49    void display() {
50        cout << "Resource size: " << size << endl;
51    }
52};
53
54int main() {
55    {
56        Resource res1(10);
57        res1.display();
58        
59        // Copy constructor prevents shallow copy issues
60        Resource res2 = res1;
61        res2.display();
62        
63    }  // Destructors called automatically
64    
65    cout << "\nAll resources properly freed" << endl;
66    
67    return 0;
68}