What are weak pointers in C++?

What are weak pointers in C++?

Weak pointers are a type of smart pointer in C++ that do not affect the reference count of the object they point to.

How do weak pointers help prevent memory leaks?

They help prevent memory leaks by allowing you to reference an object without taking ownership, thus avoiding circular references.

Can you give me an example of using weak pointers?

Sure! Here's a simple example:

#include <iostream>
#include <memory>

class MyClass {
public:
    MyClass() { std::cout << "MyClass created" << std::endl; }
    ~MyClass() { std::cout << "MyClass destroyed" << std::endl; }
};

int main() {
    std::shared_ptr<MyClass> sharedPtr = std::make_shared<MyClass>();
    std::weak_ptr<MyClass> weakPtr = sharedPtr;

    if (auto tempPtr = weakPtr.lock()) {
        std::cout << "Weak pointer is valid" << std::endl;
    } else {
        std::cout << "Weak pointer is expired" << std::endl;
    }
    return 0;
}

What happens if the shared pointer is deleted?

If the shared pointer is deleted, the weak pointer will no longer be able to lock onto the object, and any attempt to access it will indicate that it has expired.