advanced patterns of std::function with std::bind and member functions in C++17
I need some guidance on I'm working with an scenario when using `std::function` in combination with `std::bind` to bind a member function of a class in C++17. The code compiles without errors, but the behavior at runtime is not what I expect. I have a class `Counter` that has a method `increment()`, which increments a private member variable `count`. I'm trying to bind this method so that it can be called through a `std::function`. Here's the relevant code: ```cpp #include <iostream> #include <functional> class Counter { private: int count; public: Counter() : count(0) {} void increment() { count++; std::cout << "Count: " << count << '\n'; } }; int main() { Counter c; std::function<void()> func = std::bind(&Counter::increment, &c); func(); // First call func(); // Second call return 0; } ``` When I run this code, I see the output as expected: ``` Count: 1 Count: 2 ``` However, if I modify the `Counter` class to add a second method that returns the current count: ```cpp int getCount() const { return count; } ``` and I try to bind this `getCount` method in the same way: ```cpp std::function<int()> countFunc = std::bind(&Counter::getCount, &c); std::cout << "Current Count: " << countFunc() << '\n'; ``` I get the output: ``` Current Count: 0 ``` This seems incorrect because I expect it to reflect the count after the `increment` calls. After some debugging, I realized I might be working with an scenario with the function binding and the state of `count`. I’ve also checked whether `getCount()` is properly accessing the member variable, and it is. Is there something I am misunderstanding about the binding of member functions or the scope of the member variable, especially when mixing calls to different member functions? Any insights or best practices on how to manage this would be greatly appreciated. I'm using GCC 9.3.0 with C++17 standard enabled. The stack includes C++ and several other technologies. Is there a simpler solution I'm overlooking? Any help would be greatly appreciated!