#include <iostream>
#include <string>
#include <map>
 
typedef void(*FUNCPTR)(double*, int); // our typedef
std::map<std::string, FUNCPTR> func_map;
 
// some functions
void f1(double*, int) {std::cout << "f1" << std::endl;}
void f2(double*, int) {std::cout << "f2" << std::endl;}
 
// call them via an invoking function
void myMainFit(const std::string& which, double* ptr, int val)
{
    if (func_map.find(which) != func_map.end()) // indeed the function was added
        func_map[which](ptr, val);
    else
    {
        std::cerr << "Function \"" << which << "\" is not in the map!\n";
        return; // or throw
    }
}
 
int main()
{
    // add functions to the map
    func_map["first"] = &f1;
    func_map["second"] = &f2;
    myMainFit("first", nullptr, 42);
    myMainFit("second", nullptr, 20);
    myMainFit("inexistent", nullptr, 10);
}
 

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