Problems with std::shared_ptr and custom deleters in C++11
Quick question that's been bugging me - I keep running into I've looked through the documentation and I'm still confused about I tried several approaches but none seem to work... I'm encountering a problem when trying to use `std::shared_ptr` with a custom deleter in my C++11 code. Specifically, I want to manage a resource that requires some cleanup when it's no longer needed. I defined a custom deleter function, but I keep getting an unexpected behavior when I try to reset the shared pointer. Here's a simplified version of my code: ```cpp #include <iostream> #include <memory> struct Resource { Resource() { std::cout << "Resource acquired" << std::endl; } ~Resource() { std::cout << "Resource destroyed" << std::endl; } }; void customDeleter(Resource* r) { std::cout << "Custom deleter called" << std::endl; delete r; } int main() { std::shared_ptr<Resource> ptr(new Resource(), customDeleter); ptr.reset(); // Expecting customDeleter to be called ptr.reset(new Resource()); // Should call the new Resource constructor return 0; } ``` When I run this code, I expect the output to show that the custom deleter is called when I reset the pointer. However, I see: ``` Resource acquired Resource destroyed Custom deleter called Resource acquired ``` It looks like the custom deleter is not being invoked as expected during the first `reset()` call. Instead, the resource seems to be destroyed immediately. I thought that the custom deleter would be responsible for cleaning up whenever the `shared_ptr` goes out of scope or is reset. I've also tried using `std::make_shared`, but that doesn't allow me to specify a custom deleter. Is there a specific reason for this behavior? Am I misunderstanding how `std::shared_ptr` manages its resources with custom deleters? How can I fix this to ensure that the custom deleter is called as intended? I'd really appreciate any guidance on this. My development environment is Windows. Has anyone else encountered this? This is my first time working with C++ LTS. Any pointers in the right direction? This is happening in both development and production on Ubuntu 20.04. What would be the recommended way to handle this? This is part of a larger microservice I'm building.