Javas class <?> Equivalent in C ++

Question

So, I am learning C ++ and want to write an entity system. To do this, I need to know what type the component has when I add it to the object. In java, I would just do something like this:

Class<?> someClass = myComponent.class;

Is there something equivalent in C ++? I tried typeid (myComponent), but this does not work in such situations.

ExtComponent* extended = new ExtComponent();
Component* base = dynamic_cast<Component>(extended);
std::cout << typeid(base).name();

This returns a "Component class", but I would like something that returns an "ExtComponent class" in such a situation. How to do it.

Answer 1

If you correctly understood that you want to receive a dynamic type of object. (not the type of the variable itself, but what this variable belongs to (really)

Typeid will work because:

N3337 5.2.8 / 2:

typeid glvalue , (10.3), std:: type_info, (1.8) (, type), glvalue [...]

, (, ), , , .

typeid , ( type_info , ):

Base *b = new Base;
...
typeid(*b); //not typeid(b)

Answer 2

. . ++. , , .

, , , . , :

template<typename>
void type_id(){}

using type_id_t = void(*)();

. std::any, boost::any, ++ 17.

struct Entity {
    template<typename T>
    void assign(T component) {
        components[type_id<T>] = component;
    }

    template<typename T>
    T& retrieve() {
        return std::any_cast<T>(components[type_id<T>]);
    }

private:
    std::map<type_id_t, std::any> components;
};

. :

Entity entity;

entity.assign(MyClass{});

MyClass& mc = entity.retreive<MyClass>();

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