This might be a silly question, but I'm working with a memory leak in my C++20 application while trying to use `std::unique_ptr` with a custom deleter. Here's a simplified version of my code: ```cpp #include #include class MyClass { public: MyClass() { std::cout << "MyClass created" << std::endl; } ~MyClass() { std::cout << "MyClass destroyed" << std::endl; } }; void customDeleter(MyClass* ptr) { delete ptr; std::cout << "Custom deleter called" << std::endl

Unexpected Memory Leak When Using std::unique_ptr with Custom Deleter in C++20

👀 Views: 71 💬 Answers: 1 📅 Created: 2025-06-06

This might be a silly question, but I'm working with a memory leak in my C++20 application while trying to use `std::unique_ptr` with a custom deleter. Here's a simplified version of my code: ```cpp #include <iostream> #include <memory> class MyClass { public: MyClass() { std::cout << "MyClass created" << std::endl; } ~MyClass() { std::cout << "MyClass destroyed" << std::endl; } }; void customDeleter(MyClass* ptr) { delete ptr; std::cout << "Custom deleter called" << std::endl; } int main() { std::unique_ptr<MyClass, decltype(&customDeleter)> ptr(new MyClass(), customDeleter); // Intentionally not resetting or releasing the pointer return 0; } ``` When I run this code, I'm expecting `MyClass destroyed` and `Custom deleter called` to be printed when the program exits, but instead, I see that the destructor is not called, and the memory allocated for `MyClass` seems to leak. I've tried adding `ptr.reset()` and `ptr.release()`, but even when I manually call the reset in different scopes, the scenario continues. My compiler is GCC 11.2, and I’m compiling with `-fsanitize=address` to check for memory issues. I've also checked other usages of `std::unique_ptr` in the project, and they work as expected. Is there something specific about using custom deleters that I might be missing, or is there a known scenario with this in C++20? Any help would be greatly appreciated! What's the best practice here?