Dynamic_Cast指针仅在获取成员时崩溃

Question

我有一个函数，它接受一个Cp指针的向量，并将它们dynamic_cast成为派生指针的指针。当我尝试获取派生类的成员变量时，它崩溃了：

void DrawSystem::update(vector<Cp*> currentArgs)
{
    cout << currentArgs[0]->type;
    //Doesn't crash here
    GraphicsCp* graphics = dynamic_cast<GraphicsCp*>(currentArgs[0]);
    cout << graphics->type; //Crashes here
    sf::Vector2f pos = dynamic_cast<PosCp*>(currentArgs[1])->pos;
    cout << pos.x << " || " << pos.y << endl;
}

有谁知道这是为什么？

编辑： 以下是所有相关代码：

void GameObject::updateSystems() {
    for(vector<System*>::const_iterator i = Systems.begin(); 
        i != Systems.end(); 
        ++i) {
        vector<Cp*> args;
        for(vector<cptype>::const_iterator j = (*i)->args.begin(); 
            j != (*i)->args.end(); 
            ++j) {
            args.push_back(Cps[*j]);
        }
        (*i)->update(args);
    }
}

---

class GameObject {
    public:
        GameObject();
        virtual ~GameObject();

        void addCp(const cptype&, Cp);
        void addSystem(const systype&);

        map <cptype, Cp*> Cps;
        vector <System*> Systems;

        void updateSystems();
        virtual void update() {}
        virtual void draw() {}
        virtual bool isVisible() { return false; }
};

---

class GraphicsCp : public Cp {
    public:
        GraphicsCp(); //TEMP
        GraphicsCp(sf::Texture*, sf::Vector2f);
        virtual ~GraphicsCp();

        sf::Sprite sprite;
        sf::Vector2f frameDim;
        sf::Vector2i currentTextureRectPos;

        void update(Player& player, sf::RenderWindow&); //TEMP
    private:
        sf::RectangleShape rectangle; //TEMP
};

---

class Cp {
    public:
        Cp();
        virtual ~Cp();

        virtual void update() {} //TEMP

        cptype type;
};

---

Player::Player() {
    addCp("Pos", PosCp());

    sf::Texture* texture = &Game::level.levelImageManager.playerSprite;
    sf::Vector2f frameDim(54, 93);
    addCp("Graphics", GraphicsCp(texture, frameDim));

    addSystem("Draw");
}

void GameObject::addCp(const cptype& type, Cp cp) {
    Game::level.levelCpManager.CpVecs[type].push_back(cp);
    Cps[type] = &Game::level.levelCpManager.CpVecs[type].back();
}

void GameObject::addSystem(const systype& type) {
    Systems.push_back(Game::level.levelSystemManager.systems[type].get());
}