lua_EntitySmartPtr

struct lua_EntitySmartPtr
{
    std::weak_ptr<TangibleEntity> weak;
    std::shared_ptr<TangibleEntity> shared;

    bool expired() const { return weak.expired(); }

    bool lock() {
        shared = weak.lock();
        return shared != nullptr;
    }
    void unlock() {
        shared = {};
    }
    TangibleEntity* ptr() { return shared.get(); }
};