Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.
Lære Breaking Circular References With Weak Pointers | Weak Pointers
C++ Smart Pointers

bookBreaking Circular References With Weak Pointers

Weak pointers are designed to break circular references. By replacing a std::shared_ptr in a circular dependency with a std::weak_ptr, we prevent objects from unintentionally extending each other's lifetimes, allowing proper destruction.

main.cpp

main.cpp

copy
12345678910111213141516171819202122232425
#include <iostream> #include <memory> class Node { public: Node() { std::cout << "Node constructed." << std::endl; } ~Node() { std::cout << "Node destructed." << std::endl; } // A weak pointer to the next element prevents circular ownership. std::weak_ptr<Node> next; }; int main() { // Creating three Node objects. std::shared_ptr<Node> node1 = std::make_shared<Node>(); std::shared_ptr<Node> node2 = std::make_shared<Node>(); std::shared_ptr<Node> node3 = std::make_shared<Node>(); // Creating a list where the last node's next is a weak pointer node1->next = node2; node2->next = node3; node3->next = node1; // Now when node1, node2, and node3 go out of scope, their destructors will be called }

The circular reference problem is resolved by changing next from a std::shared_ptr to a std::weak_ptr. Follow the comments in the code for a clearer understanding. Run the code to confirm that the destructors are now called properly no memory leaks!

question mark

The following code has two shared pointers A and B both sharing a resource. Modify it so that B becomes a weak pointer.

Select the correct answer

Alt var klart?

Hvordan kan vi forbedre det?

Takk for tilbakemeldingene dine!

Seksjon 4. Kapittel 3

Spør AI

expand

Spør AI

ChatGPT

Spør om hva du vil, eller prøv ett av de foreslåtte spørsmålene for å starte chatten vår

Awesome!

Completion rate improved to 5.56

bookBreaking Circular References With Weak Pointers

Sveip for å vise menyen

Weak pointers are designed to break circular references. By replacing a std::shared_ptr in a circular dependency with a std::weak_ptr, we prevent objects from unintentionally extending each other's lifetimes, allowing proper destruction.

main.cpp

main.cpp

copy
12345678910111213141516171819202122232425
#include <iostream> #include <memory> class Node { public: Node() { std::cout << "Node constructed." << std::endl; } ~Node() { std::cout << "Node destructed." << std::endl; } // A weak pointer to the next element prevents circular ownership. std::weak_ptr<Node> next; }; int main() { // Creating three Node objects. std::shared_ptr<Node> node1 = std::make_shared<Node>(); std::shared_ptr<Node> node2 = std::make_shared<Node>(); std::shared_ptr<Node> node3 = std::make_shared<Node>(); // Creating a list where the last node's next is a weak pointer node1->next = node2; node2->next = node3; node3->next = node1; // Now when node1, node2, and node3 go out of scope, their destructors will be called }

The circular reference problem is resolved by changing next from a std::shared_ptr to a std::weak_ptr. Follow the comments in the code for a clearer understanding. Run the code to confirm that the destructors are now called properly no memory leaks!

question mark

The following code has two shared pointers A and B both sharing a resource. Modify it so that B becomes a weak pointer.

Select the correct answer

Alt var klart?

Hvordan kan vi forbedre det?

Takk for tilbakemeldingene dine!

Seksjon 4. Kapittel 3
some-alt