c++ - 如何调用返回 double 或字符串并将其保存在 map 上但作为对象的类的方法

Question

编译时出现错误:无法在赋值中将‘std::string {aka std::basic_string}’转换为‘std::map, Object*>::mapped_type {aka Object*}’

myMap["objectA"] = aa->str();

这是我的程序:

class Object{
public:
    virtual void test() =0;
    virtual string str() {}
};

class A : public Object{
public:
  void test(){
    int a = 23.58;
    cout << a;
  }
  string str(){
    return "a";
  }
};

class B : public Object{
public:
  void test(){
    cout << "B::play()\n";
  }
};

class C : public Object{
public:
  void test(){
    cout << "C::play()\n";
  }
};


int main() {
  map<string, Object*> myMap;

  A* aa = new A;

  myMap["objectA"] = aa->str();
  myMap["objectB"] = new B;
  myMap["objectC"] = new C;

  map<string, Object*>::iterator it;
  for(it = myMap.begin(); it != myMap.end(); it++){
    (*it).second->test();
    delete (*it).second;
  }

如何解决该 map 上保存不同类型数据的问题？

Answer 1

您不能添加 std::string作为 std::map<std::string, Object*> 的值.您可以添加指针 aa .

myMap["objectA"] = aa;