Using std::shared_ptr with custom deleter leads to double-free scenarios in C++17
I'm trying to implement Hey everyone, I'm running into an issue that's driving me crazy..... I'm working with a double-free behavior when using `std::shared_ptr` with a custom deleter in my C++17 project. I have a class `Resource` that manages some dynamic memory, and I want to ensure that the memory is properly released when the `shared_ptr` goes out of scope. Here's a simplified version of my setup: ```cpp #include <iostream> #include <memory> class Resource { public: Resource() { std::cout << "Resource acquired." << std::endl; } ~Resource() { std::cout << "Resource destroyed." << std::endl; } }; void customDeleter(Resource* res) { delete res; std::cout << "Custom deleter called." << std::endl; } int main() { std::shared_ptr<Resource> ptr1(new Resource(), customDeleter); std::shared_ptr<Resource> ptr2 = ptr1; // Sharing ownership return 0; } ``` When I run this code, I get a runtime behavior: `double free or corruption (out)`. I tried using `std::make_shared` initially, but it doesn't allow for a custom deleter. My assumption was that since `ptr2` is a copy of `ptr1`, the reference count would manage the resource correctly without calling the custom deleter more than once. However, it seems like the custom deleter is being invoked multiple times. Additionally, I checked the reference count using `ptr1.use_count()` and confirmed it reflects the expected count of `2`. I also ensured there's no other part of the code deleting the `Resource` instance directly. Is there a way to safely use `std::shared_ptr` with a custom deleter while avoiding this double-free scenario? What am I missing here? I'm working on a CLI tool that needs to handle this. Thanks in advance! I'm working on a web app that needs to handle this. I'd really appreciate any guidance on this. The project is a CLI tool built with C++. Is this even possible? Is this even possible? For context: I'm using C++ on CentOS. Thanks for any help you can provide!