👀 Views: 2 💬 Answers: 1 📅 Created: 2025-06-06

c++ std-function std-bind cpp

I've been banging my head against this for hours. I'm working on a personal project and I'm working with an scenario where `std::function` seems to not invoke correctly when combined with `std::bind`. I'm using C++20 and trying to bind a member function of a class to a `std::function` but when I call the function, it doesn't behave as expected. Here's a simplified version of what I have: ```cpp #include <iostream> #include <functional> class MyClass { public: void display(int x) { std::cout << "Value: " << x << std::endl; } }; int main() { MyClass obj; std::function<void()> func = std::bind(&MyClass::display, &obj, 42); func(); // Expected output: Value: 42 } ``` However, I get no output at all when I run this code. I've double-checked that the `MyClass` instance is properly created and the member function should be callable. I also tried using a regular function instead, and that worked fine: ```cpp void simpleFunction(int x) { std::cout << "Simple Value: " << x << std::endl; } std::function<void()> simpleFunc = std::bind(simpleFunction, 42); simpleFunc(); // Outputs: Simple Value: 42 ``` It's peculiar that calling the member function through `std::bind` doesn't produce any output. I've ensured that I'm using the correct member function signature, and I've run this on both GCC 11.2 and Clang 12.0 with the same results. What could be causing the `std::function` not to invoke the bound member function correctly? I'm working on a service that needs to handle this. What am I doing wrong? Any ideas what could be causing this?