std::unique_ptr with Custom Deleter Not Being Called in C++17
I'm confused about I'm stuck on something that should probably be simple. I've been struggling with this for a few days now and could really use some help. I'm encountering an issue with `std::unique_ptr` that uses a custom deleter. I have a class that allocates resources dynamically, and I'm using a custom deleter to clean up these resources. However, when the `unique_ptr` goes out of scope, the custom deleter doesn't seem to be called, leading to a memory leak. I've already verified that the `unique_ptr` is correctly initialized with the custom deleter, but it seems like it's not getting invoked. Here's a minimal example of what I'm working on: ```cpp #include <iostream> #include <memory> struct Resource { Resource() { std::cout << "Resource acquired!\n"; } ~Resource() { std::cout << "Resource destroyed!\n"; } }; void customDeleter(Resource* res) { std::cout << "Custom deleter called!\n"; delete res; } int main() { std::unique_ptr<Resource, decltype(&customDeleter)> ptr(new Resource(), customDeleter); // ptr.reset(); // Uncommenting this line works fine. return 0; } ``` In the example above, I expect the output to include "Custom deleter called!" when `ptr` goes out of scope. However, I'm not seeing that output. I have also tried adding `ptr.reset()` before the end of the program, which does trigger the custom deleter, but I want the custom deleter to be called automatically upon exiting `main()` without explicitly calling `reset()`. I've checked that the `std::unique_ptr` is not going out of scope prematurely. Is there something I might be missing here? Is there a specific behavior in C++17 that I should be aware of that could affect the custom deleter? Any insights would be appreciated! My development environment is Ubuntu. How would you solve this? I'm working on a API that needs to handle this. What am I doing wrong? This is for a mobile app running on macOS. Any examples would be super helpful.