std::unique_ptr Resetting with Custom Deleter Not Releasing Resource as Expected
I've run into an scenario where a `std::unique_ptr` with a custom deleter is not releasing resources as expected upon reset. My setup involves a custom class `Resource` that manages a dynamically allocated array. The custom deleter is supposed to call `delete[]` on this array, but it seems to be malfunctioning. Here's a simplified version of the code: ```cpp #include <iostream> #include <memory> class Resource { public: Resource(size_t size) : size(size), data(new int[size]) {} ~Resource() { std::cout << "Resource destroyed" << std::endl; } private: size_t size; int* data; }; void customDeleter(Resource* res) { std::cout << "Custom deleter called" << std::endl; delete res; // Wrong deletion method here } int main() { std::unique_ptr<Resource, decltype(&customDeleter)> resPtr(new Resource(10), customDeleter); resPtr.reset(new Resource(20)); return 0; } ``` When I run this code, I notice that the first `Resource` instance is not being destroyed properly. Instead of printing "Resource destroyed" when I call `resPtr.reset`, I see the custom deleter is invoked, but the destruction of the previous resource doesn't occur as expected. The output shows "Custom deleter called" but the destructor for the `Resource` class is never reached. I've tried changing the deleter to simply call `delete res;`, which should work, but I still see the same output. I suspect that the scenario is related to how I'm handling the custom deleter with `std::unique_ptr`, but I need to seem to pinpoint the exact question. I'm using C++17, and this behavior is causing memory leaks in my application. Could anyone guide to figure out what’s going wrong here? Any insights or suggestions would be greatly appreciated!