如何从基数 classes 的向量中获取派生 class 的名称

Question

所以我的代码中有一个基 classes 向量和几个错误，这意味着我需要知道哪个派生 class 正在调用多态方法：

class Base {
  virtual void render() {}
}

class Derived1 {
  void render() override {/*do stuff*/}
}

class Derived2 {
  void render() override {/*do stuff*/}
}

class Game {
  std::vector<Base> baseVec;

  void render() {
    for(Base b: baseVec) {
      b.render();
      //std::cout << typeid(b).name() << std::endl; prints base class' name, and requires some logic to unmangle the actual name
      //std::cout << std::type_index(typeid(b)).name() << std::endl; also prints base class' name
      //std::cout << typeNames[std::type_index(typeid(b))] << std::endl; typeNames is an unordered_map<std::type_index, std::string> - still prints the base class' name, and the list has to be punched in by hand (bad)
    }
  }
}

Answer 1

根据我对您的要求的理解，根据您的要求修改了以下代码：

class Base {
public:
    virtual void render() = 0;
};

class Derived1: public Base  {
    void render() override { std::cout << "Derived1"<<std::endl; }
};

class Derived2: public Base {
    void render() override { std::cout << "Derived2" << std::endl; }
};

int main()
{
    std::vector<Base*> baseVec;
    Derived1 d;
    Derived2 d1;
    baseVec.push_back(&d);
    baseVec.push_back(&d1);

        for (auto& b : baseVec)
        {
            b->render();
            std::cout << typeid(*b).name() << std::endl; 
        }

    return 0;
}

输出：

Derived1
class Derived1
Derived2
class Derived2

typeid 正在使用 => typeid(*b).name().

解析您的名字

typeid explained

如何从基数 classes 的向量中获取派生 class 的名称

How to get the name of a derived class from a vector of base classes

c++

inheritance

types

typeinfo