implementing Dynamic Binding in C++ When Using Smart Pointers with Inheritance
After trying multiple solutions online, I still can't figure this out. I'm working with a question with dynamic binding when using `std::shared_ptr` in a class hierarchy. I have a base class `Shape` and derived classes `Circle` and `Square`. I want to store different shapes in a vector and call their `draw()` method polymorphically. However, I'm getting unexpected behavior where calling `draw()` on elements from the vector does not invoke the derived class implementation as expected. Here’s a simplified version of my code: ```cpp #include <iostream> #include <memory> #include <vector> class Shape { public: virtual void draw() const { std::cout << "Drawing Shape" << std::endl; } virtual ~Shape() = default; }; class Circle : public Shape { public: void draw() const override { std::cout << "Drawing Circle" << std::endl; } }; class Square : public Shape { public: void draw() const override { std::cout << "Drawing Square" << std::endl; } }; int main() { std::vector<std::shared_ptr<Shape>> shapes; shapes.push_back(std::make_shared<Circle>()); shapes.push_back(std::make_shared<Square>()); for (const auto& shape : shapes) { shape->draw(); // This should call Circle or Square's draw() } return 0; } ``` When I run this code, I expect to see: ``` Drawing Circle Drawing Square ``` However, I sometimes see the output from the base class `draw()` instead, as if the objects were not recognized as their derived types. I've ensured that I'm not slicing the objects; the `std::shared_ptr` should handle that. I've also confirmed that I have the correct override specifier in the derived classes. I'm compiling with g++ 11.2.0. Is there something I'm missing in my usage of smart pointers or the way I'm structuring my classes that could lead to this behavior? This is my first time working with C++ 3.10. Any pointers in the right direction?