An example of how shared_ptr goes the extra mile when you write bad classes

slicing.cpp

class Base {
    public:
    Base(size_t len);
    ~Base();
    private:
    char* data_;
};

Base::Base(size_t len):
    data_(new char[len]) {
    std::cout << "Base constructed\n";
}

Base::~Base() {
    std::cout << "Base deleted\n";
    delete[] data_;
}

class Derived: public Base {
    public:
    Derived(size_t len);
    ~Derived();
    private:
    int* count_;
};

Derived::Derived(size_t len):
    Base::Base(len),
    count_(new int(0)) {
    std::cout << "Derived constructed\n";
}

Derived::~Derived() {
    std::cout << "Derived deleted\n";
    delete count_;
}

int main() {
    // What is printed?
    {
        std::shared_ptr<Base> sp = std::make_shared<Derived>(16);
    }
    
    return 0;
}