What is a weak_ptr in C++11?

What is a weak_ptr in C++11?

A weak_ptr is a smart pointer in C++11 that holds a non-owning reference to an object managed by a shared_ptr.

How does weak_ptr help prevent memory leaks?

It helps prevent memory leaks by allowing you to break circular references between shared_ptrs, thus enabling proper memory management.

Can you give an example of using weak_ptr?

Sure! Here's a simple example:

#include <iostream>
#include <memory>

class Node {
public:
    std::shared_ptr<Node> next;
    Node() { std::cout << "Node created" << std::endl; }
};

int main() {
    std::shared_ptr<Node> node1 = std::make_shared<Node>();
    std::weak_ptr<Node> weakNode = node1;
    std::cout << "Weak pointer use: " << (weakNode.expired() ? "expired" : "valid") << std::endl;
}

What happens if the shared_ptr is deleted?

If the shared_ptr is deleted, the weak_ptr will become expired, meaning it no longer points to a valid object.