Question

I have 5 classes that are used as operators :

TurnOn , TurnOff , PushBox , Exit , Enter

And I have for each type , a string that holds a description of that type .

For instance :

class Places {

enum Type { Room1 ,Room2 ,Room3 ,Room4 };


// more stuff

};
TurnOn turnOn(Places::Room1);
string turnOnString = "TurnOn(Room1)" ;

I want to store the info in a map , so I have 5 maps for each operator :

map <string , TurnOn > opeatorTurnOn;
map <string , TurnOff > opeatorTurnOff ;
map <string , PushBox > opeatorTPushBox ;
map <string , Exit > opeatorExit ;
map <string , Enter > opeatorEnter ;

But now I have 5 maps with the same concept : a string with its operator .

How can I store the operators in one map so I won’t have to hold 5 maps with the same concept ?

Answer 1

It depends on how your operator classes are implemented (we have very little information), but I’d make a map of callables, something similar to this:

#include <iostream>
#include <functional>
#include <map>

struct op1
{
    void operator()(int i) { std::cout << "op1::operator() " << i << "\n"; }
};

struct op2
{
    void operator()(int i) { std::cout << "op2::operator() " << i << "\n"; }
};

int main()
{
    std::map<std::string, std::function<void(int)>> ops;
    ops["1"] = op1{};
    ops["2"] = op2{};
    ops["1"](42);
    ops["2"](42);
}

You could also always wrap the ops in lambdas if you don’t use the operator() overloading.