Undefined behavior when using std::deque with custom data types in C++20
Quick question that's been bugging me - I'm trying to debug I'm working with undefined behavior when trying to store custom objects in a `std::deque` in C++20..... Specifically, my custom class `MyData` has a complex destructor that is supposed to release resources, but when I try to insert and remove instances of `MyData`, I occasionally get a crash or corrupted data. Here’s a simplified version of my code: ```cpp #include <deque> #include <iostream> class MyData { public: MyData(int id) : id_(id) { std::cout << "Constructing MyData: " << id_ << '\n'; } ~MyData() { std::cout << "Destructing MyData: " << id_ << '\n'; } int id_; }; int main() { std::deque<MyData> myDeque; for (int i = 0; i < 10; ++i) { myDeque.emplace_back(i); } myDeque.pop_front(); // Removing the front element return 0; } ``` When I run this code, I sometimes see a segmentation fault when trying to pop elements after inserting a large number of them. I suspect it might be related to how `std::deque` manages its memory or how my destructor interacts with it. I've also noticed that the behavior seems to occur mostly when I run the code in a debug build versus a release build, which adds to my confusion. I've tried switching to `std::vector` and my code runs without issues, but I need the specific benefits of `std::deque` for my application. Is there something I'm missing regarding `std::deque`'s memory management? How can I safely manage my custom objects in a `std::deque`? Any insights would be greatly appreciated! For context: I'm using Cpp on Windows. Is there a better approach? What would be the recommended way to handle this? I'm on macOS using the latest version of Cpp. Any advice would be much appreciated.