#include <iostream>
#include <functional>
#include <memory>
#include <vector>

// Type-erased Instrument class using std::function for polymorphic play
class Instrument {
public:
    // Constructor accepts any object with a play() function
    template <typename T>
    Instrument(T instrument)
        : play_func([instrument = std::make_shared<T>(std::move(instrument))]() { instrument->play(); })
    {}

    // Polymorphic play call
    void play() const {
        play_func();
    }

private:
    std::function<void()> play_func;  // Holds the type-erased play functionality
};

// Guitar class
class Guitar {
public:
    void play() const {
        std::cout << "Strumming the guitar!" << std::endl;
    }
    ~Guitar() {
        std::cout << "Guitar destructor called." << std::endl;
    }
};

// Drums class
class Drums {
public:
    void play() const {
        std::cout << "Beating the drums!" << std::endl;
    }
    ~Drums() {
        std::cout << "Drums destructor called." << std::endl;
    }
};

int main() {
    std::vector<Instrument> instruments;

    // Directly emplacing instruments into the vector
    instruments.emplace_back(Guitar());
    instruments.emplace_back(Drums());

    // Demonstrating polymorphism
    for (const auto& instrument : instruments) {
        instrument.play();  // Calls the correct play function
    }

    // Destructors will automatically be called when the objects go out of scope
    return 0;
}