Qfyilyi

I need to make map with value of class's. Now it's look like:

if (string=="Reg") {

Registration Registration(Data);

    Registration.GetResult();

}



if (string=="Auth") {

Login Login(Data);

    Login.GetResult();

}

.....

and I would like to do like:

map <std::string, class_name> ClassList;

ClassList ["Reg"] = Registration;

ClassList ["Auth"] = Login;



......



ClassList [string](Data).GetResult();

Thanks for help!

One way is to have a (unordered?) map of functions:

std::unordered_map<std::string, std::function<void(DataCls)>> map;

map["Reg"] = (DataCls Data) {

    Registration Registration(Data);

    Registration.GetResult();

};

map["Auth"] = (DataCls Data) {

    Login Login(Data);

    Login.GetResult();

};

...

map[string](Data);

This can be simplified with this templated function:

template<class T>

void Handler(DataCls Data) {

    T instance(Data);

    instance.GetResult();

};



map["Reg"] = Handler<Registration>;

map["Auth"] = Handler<Login>;

...

map[string](Data);

I would recommend the following inheritance hierarchy:

#include <iostream>

#include <string>

#include <map>



class IOperation

{

public:

    virtual ~IOperation(){}

    virtual int GetResult() = 0;

};



class Registration : public IOperation

{

public:

    int GetResult() override

    {

        return 1;

    }

};



class Login : public IOperation

{

public:

    int GetResult() override

    {

        return 2;

    }

};



int main()

{

    std::map<std::string, IOperation *> classList;



    classList["Reg"] = new Registration();

    classList["Auth"] = new Login();



    std::string cmd = "Auth";

    std::cout << classList[cmd]->GetResult();

}