👀 Views: 8664 💬 Answers: 1 📅 Created: 2025-06-10

c++ memory-management smart-pointers cpp

I've been struggling with this for a few days now and could really use some help... I'm working on a personal project and I'm dealing with a memory leak issue in my C++ application when using `std::shared_ptr` for a custom object graph. I have two classes, `Node` and `Edge`. Each `Node` holds a reference to its connected `Edge` objects, and each `Edge` holds a reference back to its originating `Node`. I thought `std::shared_ptr` would manage the memory correctly, but I'm seeing signs of a memory leak when I run my application. Here's a simplified version of the relevant code: ```cpp #include <iostream> #include <memory> #include <vector> class Edge; class Node { public: std::shared_ptr<Edge> edge; ~Node() { std::cout << "Node destroyed" << std::endl; } }; class Edge { public: std::shared_ptr<Node> fromNode; ~Edge() { std::cout << "Edge destroyed" << std::endl; } }; int main() { std::shared_ptr<Node> n1 = std::make_shared<Node>(); std::shared_ptr<Node> n2 = std::make_shared<Node>(); std::shared_ptr<Edge> e1 = std::make_shared<Edge>(); n1->edge = e1; e1->fromNode = n2; // Circular reference here return 0; } ``` When I run this code, I notice that the destructors for `Node` and `Edge` are not being called, indicating that these objects are not being freed. I suspect that the circular reference created by having `Node` pointing to `Edge` and vice versa is causing the issue. What would be the best practice to resolve this circular dependency? Should I consider using `std::weak_ptr` for one of the pointers to break the cycle? If so, how would I implement that in my design without losing the required references? Any guidance or examples would be greatly appreciated! My development environment is macOS. Any ideas what could be causing this? Is there a better approach?